Front end stays down just fine. I have a +4 swingarm on it. You should be able to eat 450s for breakfast, lunch and dinner. I rode it with a stock swingarm a few times and it woud wheelie out of the tree shots.The dyno results are posted on this site, here is the link
http://bansheehq.com/forums/index.php?showtopic=107867&st=30. You will be very happy with this setup. I was at winchester last weekend.