DI2. Talk to me. If I was sinking max of £1k on a groupset should I try to go budget eTap or full fat di2. Will be with hydraulic discs (which makes me think di2 for shimano levers & calipers is the better option than SRAM?).
Depends really, with both DA Di2 and eTap, I'd say for me they both have pros and cons:
eTap Pros: So simple to setup, charging is easy with removable batteries, quick charge, get used to the double paddle front change and it's nice, great shifting
eTap Cons: paddles and levers feel a little less robust than the di2
Di2 pros: smooth as shifting, more potential features/ integrations (BT, top hood buttons, sync shifting etc.), feels really well made
Di2 Cons: man so many cables...internal batteries and routing, charging/ junction box location can be a pain/ less sightly
If I was to build another, what would I pick? eTap for me. Ease of use and setup wins out, but I can't fault the di2 in any way, other than I wouldn't want to **** about routing it all. You're paying about 450 for each RD, but with di2 you dont get the battery etc with that, whereas you do with etap. I bought all my etap stuff on ebay and it was all either new or as new and it cost me under a grand in total.