OK the firstbloods are a true all mountain ski, with a pretty average turning radius and 91 underfoot i believe. Recommended for these type of skis can go anywhere between -2.5cm back from true center to -4 or -5 depending on the ski. I don't know where recommended on your skis are. If you want to get into more park, the typical suggestion is mount closer to center, for even swing weight and better switch performance. You said you didn't do a lot of switch though, so closer to center is not necessarily needed but may be a bit more fun. The main thing if you are skiing on lots of groomers and like making turns, the closer you mount to center, the more you will work against the sidecut and thus reduce the chances of the ski skiing the way it was designed. Not knowing any more that I do about you, my recommendation would be to mount at -2.5cm or -3cm from true center, or quite possibly the "recommended" line. If there's 2 of those, pick the one more forward because you want to mess around in the park a little more and that will be a bit more fun.
