I've hunted Wyoming antelope many times, but never those specific units, but I'll tell you what I have heard.
Unit 91 was last year (2012) was one of the units Eastman's listed as having "extreme winter kill". So that is a real concern.
Unit 106 on the other hand was not in the extreme winter kill area. I have seen photos of some excellent bucks from Unit 106. It is also surrounded on every side by excellent antelope units. I nearly applied there myself last year.
Three of my boys have max points or one point less than max points. We have decided to hold off applying for Wyoming with them in 2013, because of the persistent drought. Most of the core antelope areas in Wyoming are in "extreme drought". Here is a link:
Another thing, antelope begin their horn growth in November, so antelope in Wyoming are already feeling the effect of the drought for next year, no matter how the spring turns out.
With that said, it's hard not to have a good time antelope hunting in Wyoming. Fish and game will adjust tags in June according to winter kill, but it is very likely the trophy quality will be off.