are you using them for mains or surrounds ? I didn't take the time to look at the specs...
if surrounds and for mostly HT, they should be fine. there is generally a good spacing between fronts and surrounds, so a perfect timbre match is not critical. timbre helps the sounds flow with the action on the screen. across the front, the speakers are generally very close together, and a mismatch would leave a small interruption in the flow of sound. from front to back, the interruption is much less noticeable.
if you are using them for mains or for alot of SACD/DVD-audio, you should go back and match to the original set. in those cases, matching timbre is alot more critical.
in general, in-walls are pretty inefficient, and tend to have a very small sound spread. you'll have to do a good job of pointing them at your listening position if you want them to be effective.