I have a 4xT9 bonus that combines a mix of some 232 and 245s (Gloves, Chest = 232 and Shoulders/Head = 245)
I have enough frost's to purchase the T10 251 shoulders and gloves but Rawr has been telling me not to. I tried telling it that I also had 251 legs available since I will have the frosts for that soon enough but it still didn't want me to break my bonus.
The 4xT9 bonus doesn't seem that strong (<2%). I haven't examined the itemization of the T10 vs T9 pieces or what the DPS impact of the 2xT10 bonus is, but I thought it was worth getting a sanity check on the results -- especially since the 2xT10 bonus
might be a little "odd" to model.