Are you posting from a time warp?
It's a lot easier to remove a frayed-off cable head from the aero levers. IIRC, the 11s ones are better again. As for actual shifting, meh... 10s aero STIs can sometimes defy all efforts to minimise cable friction enough to perform well. There's a reason they ran the gear cables that way in the first place.
11s are much more reliable due to revised cable pull. I'm not sure, but they might have done something with the cable pull midway through 10s; I seem to recall having to get in a new matching RD when a customer upgraded his 10s levers.
If it was me I'd go straight to 11s and employ one of the methods for using it on a 10s wheel. I actually have a 10s billet cassette modified to fit on a 7s cassette body, retrofit to reduce dish on my 10s wheel that already has an off-centre rim, because I hate dish. So not a fan of 11s wheels.