Probably only you can work out which suits you best. I went through this as well and ended up going with the IA16 because I preferred to stay with a black frame and I wanted to make some other upgrades. But after getting the IA16 with intention to make those upgrades I was quite satisfied with the basic bottom end bike. The low end components served me better than I expected and to be honest I probably could have just remained with this selection for the type of courses I use (flattish to low rolling hills). Because I don't do a whole lot of shifting the low end group was sufficient. Part of it was going low end because I was transferring some items from the previous bike so I did not want to pay more. Those were some of the things that swayed my thoughts to the low end.

The insane part of me is now in upgrade mode with components that I wanted.

Wheels - Flo 60's transferred from previous bike
Crank - Quarq PM 52/36 transferred from previous bike
Saddle - Cobb 55 purchased and swapped. I have never liked the saddles that come on the bikes.
Group - etap aero purchased and waiting to be installed
TriRig Alpha One - Ordered and waiting oh so patiently and impatiently :-)


Even though I was doing some swaps and planned upgrades I do remember going through what you going through and trying to decide the better path. Another thing even if you go with the IA10 / Di2 option will you like the way it comes or will you want to refine it? There are some members here that have upgraded to Di and probably have refined the junction box and cables compared to a factory install. On my IA16 all of the cables are terrible and need to be redone, but that will be taken care of when I upgrade.

Look forward to hearing which one you choose.

edit: one other thing I forgot was the IA16 black frame in my size was available. I ordered and it was shipped that day. Other options at that time would have had a wait time for potentially weeks. When I found out this one was available I jumped on it.