Try them out and see how they feel. I mounted my Thalls -2.5 and did not really like how they skied as all my other armadas had been centered. I thought id try -2.5 for more all mountain, but I did not like it. I remounted center and I like it much better, but that's just me, you may prefer -2.5. 1 remount wont effect the ski at all as long as its done right.
Most of my skis have a least 1 remount, I barley ever get the right mount point first time.