I have the new DA 11spd. Frankly the additional cog was incidental when getting the group and to a certain extent a nuisance at first when choosing potential wheels. That being said I'm really liking having both an 11t and a 28t for my rides, and now that pretty much all the hub manufacturers have either compatible hubs or freehub swaps available looking at another wheelset is no longer a big deal. There have been some decent articles written though that wheels will be better (maybe stronger) when axle length is increased to allow for the additional spacing needed. I don't know I only have a couple hundred miles on my current wheels and they seem perfectly strong to me

With all this though, would I let something like the number of cogs direct which group to buy... not in my case. I bought Shimano DA because I prefer the style of shifting and brake performance to the SRAM, if I were to buy SRAM or Campy it would be for the same reasons if I preferred the performance of one over the other.

Good luck I'm sure you'll enjoy any group you get!