I used a SRAM RED eTAP road groupset with rim-brakes for about eight months and about 4600km. Here are my thoughts.
Setting up a new groupset isn't something I have much familiarity with. I've changed components and tweaked my bikes for the last few years, but I'm no expert. I should also point out that because I didn't want to pay three figures for a SRAM cassette I have a fairly ordinary Shimano one. I also have a Stronglight chainset because I prefer the robust and affordable square taper bottom bracket.
Despite that, setting up the eTAP was easy. Probably easier than a mechanical groupset. Apart from the brakes, there are no cables to route. There were online videos which helped, but apart from a couple of dropped chains until I adjusted the position of the front derailleur, everything just worked.
Ergonomically the eTAP shifters are wonderful to use. They are easy, comfortable and quick enough to change for my purposes. They have a positive little click and once you're used to them, require little thought or effort, even when changing multiple gears at once. This is really nice when you're tired or have cold hands. I've never had a problem changing gear with mechanical shifters, but these are noticeably easier. An added bonus is that it's easier to shift while braking, assuming you turn the pedals slowly as well.
I also bought a set of "blips" which are additional shifting buttons which can be positioned under bar tape or on aero bars and plugged into the main shifters via short wires. These are found more temperamental and found after a few rides one of them would stop working and I'd have to undo the bar tape, jiggle them around and redo them. A had a few weeks of doing this before they finally decided to work consistently. I'm not sure what the problem was. Maybe winding the bar tape slightly pulled the plug out or pre-pushed the button or maybe one wire had a partial break in it which only caused a problem at certain angles. Once working it was a small bonus to be able to shift from the bar tops without the slight extra effort of shifting position each time.
I'm not going to pretend that electronic shifting means all shifts are perfect and smooth and there's no noise or chain skip. It isn't magic. It still requires adjustment and in my experience went out of adjustment as easily as any derailleur. The equivalent of a barrel adjuster is an extra little button inside the shift lever. If you hold that down when shifting then, instead of a full shift, it does a tiny adjustment shift which is not reset the next time you do a normal shift. Thus you can make tweaks to keep the derailleur lined up with the cassette. This works really well when the bike is on a maintenance stand, but I found the little buttons really awkward to reach when riding.
Front and rear derailleurs each come with an identical battery. You can swap them between the two if you want. They also have plastic blanking plates to keep the battery sockets clean in transport. In theory the batteries will last for 1000km. I never went more than 800km without charging, but they seemed fine for that. They can be charged with a small USB charger in under an hour, so you could feasibly do this on the road or from a hub dynamo.
The batteries are supposed to be removed for transporting the bike, say on a roof rack or by train. This is apparently because the motion of the vehicle will trigger the gears to "wake up" and drain a little battery life.
For the most part the eTAP just works without problems, but I did get one issue which became a show-stopper for me.
On a couple of my longer rides I noticed that occasionally that clicking the shifters for the rear derailleur had no effect. I'd click again, sometimes several times, up and down, using the levers or the blips. Nothing. Then, ten to thirty seconds later it would come back and sometimes catch up with all the shifts I'd made. The front derailleur continued to work as normal.
At first this occurred only very occasionally, maybe for 30 seconds every few weeks. Annoying, but as I don't race it wasn't the end of the world.
Over time it got a bit worse, happening more often, once every few days. I contacted Wiggle, through whom I'd bought the gears and they said that as it was more than six months old, I'd need to provide a video of the fault occurring before I could send it for repair/replacement. Great, that's not going to be easy or safe to do while riding along! I could put the bike in a workstand to capture the issue, but could be waiting hours before it happened.
To complicate matters, my big ride of the year, PBP2019 was approaching and I had to make a decision - go with the ergonomic, but unreliable eTAP or refit my old Campagnolo mechanical groupset. Even if I could get Wiggle to agree to a replacement of the flaky eTAP, I doubted it would come back in time for the event. In the end I decided to stick with the eTAP, partly due to laziness about refitting the old groupset and getting it tweaked properly before the event. Unfortunately, about 800km into this 1200km event, the shifting got dramatically worse and, with 200km to go I couldn't get the rear derailleur to move at all. I finished OK on two gears by shifting on the front ring only, but it was a disappointing outcome for such an expensive system. I'm learning that, in general the most expensive kit is not usually more reliable than the middle of the range kit.
When I got back, providing video evidence to Wiggle was at least easy now, so they and SRAM did the right thing and replaced the rear derailleur, which I promptly put up for sale on eBay, along with the rest of the groupset.
My guess is that the power-saving motion sensor in the rear derailleur became damaged due to vibration, taking more and more violent bumps to wake it up and eventually wouldn't switch on at all.
Is the SRAM RED eTap nice to use?
Yes, it's very nice to use. The batteries add some complication in that they're another thing to remember to charge and can be stolen, but in general it is ergonomic and functional.
Do you need a SRAM RED eTAP?
No, you don't.
Well, maybe you do if you have some issues with hand mobility that bar-end or down-tube shifters won't solve. In that case think seriously about single speed or fixed gear riding. I haven't tried it but it is a simple set up which plenty of people of all ages enjoy it and seem to have few issues. But if you want shifters, mechanical ones work well for the vast majority of people.
I'm increasingly valuing reliability and simplicity. Going electronic is a nice gadget, but it doesn't revolutionise the ride. For me it's not worth the money.
Ergonomically the eTAP shifters are wonderful to use.
I'm not going to pretend that electronic shifting means all shifts are perfect and smooth and there's no noise or chain skip. It isn't magic.
I'm increasingly valuing reliability and simplicity.