I took my V20 out today for a test ride with the new SRAM Force AXS groupset. Shimano makes great stuff. I know. Shimano Di2 is probably a dream groupset, and rightly so. I almost went that route for a few reasons. 1 is that I live in Japan and see the products they put out. 2 is that I know it is a good groupset from what I hear and read. Campagnolo is also a good groupset. I have Chorus on my DF bike and it was nothing but perfect for 20,000km before I bought my V20.
With that said, I bought Shimano 105 because it is almost as good as Ultegra and Dura Ace except for a bit heavier and a little less refined.
Shimano's Di2 and Campagnolo's EPS for all intents and purposes are incredible pieces of kit for bikes. However, I went with Sram because I didn't want wire actuated derailleurs, and I didn't want to deal with sticking the battery in the frame or boom and running all the wires. Mechanical is great because every bike shop can fix it if you don't wrench on your bike yourself. I do, but for some reason, probably my own ignorance and inability to wire my V20 up, I just couldn't get my Shimano R7000 105 to keep shifting well for months at a time. I wanted to connect the parts to the bike during the initial setup, then have it perform flawlessly without measuring and cutting a bunch of wires, stringing it up, hiding the wires under the bar tape, making the exposed wires neat with cable ties or tape and all of that stuff. I'm kind of old school with tech, and always a bit skeptical when new stuff comes out that claims to be better than what was always used.
But I am thoroughly impressed with SRAM AXS. Brains in derailleurs and levers that change gears quickly, accurately and dependably without flair. The tech is dumb enough for even me to get it. Di2 and EPS was the next logical leap from mechanical, but for me it wasn't a big enough leap. Having a motor yank the wire the predetermined distance instead of pushing a lever that turned a ratchet a predetermined distance is pretty cool, but didn't do enough for me to introduce the additional responsibility of having to keep the battery charged. In more simple terms, I didn't want to push a lever that told a robot to yank the same wire instead of me. I wanted a robot to change the gears so we can eliminate the wires altogether. I am sold on SRAM AXS.