Originally Posted by
sumbikerguy123
R. That's part of it, but if any of the 10 speed Di2 parts broke and I couldn't find a replacement then a complete swap/upgrade would be in order, albeit a more expensive one.
But then again there's no guarantee a 11 speed Di2 part couldn't break also. Though the 11 speed parts are more readily available than the OOP 10 speed parts. And it would be cheaper replacing one 11 speed part, than replacing several 10 speed Di2 parts assuming you can find the parts, the again, upgrading at that point to 11 speed would make sense.
Thanks.
The point is that 10 speed DI2 is at a dead end, as well as 10 speed in general, all manufactures are moving to 11 speed from mid range up.
Given that 11 speed DI2 is now standard for both road and MTB system, you have a much better spares base than from the original DI2 which for both Ultegra and Dura Ace is now several years OOP.
If looking at a new bike, which the OP is, there is little point in looking at 10 speed, if upgrading, the cost of a 10 speed DI2 groups set could be attractive, especially if it is priced in the knowledge that its obsolete, and spares are becoming hard to come by (although I would pass on this).