Great choice in saws, but you might want to run it stock before you have it ported. I have a stock 562 and a stock 460 and I just came in from bucking and noodling up a load of 40" Elm rounds, 24" Locust, and some smaller Hackberry. With a 20" bar on the 562 and a 32" bar on the 460, the 562 is so much easier to use, handles so much better, is so much lighter and just way more fun to run I hardly ever picked up the 460. The 460 has 1hp more than the 562 but you won't miss it. To be honest, the 460 is such a disappointment that I will either sell it or have it ported. As is, there isn't enough difference in power to make up for the weight penalty.
If you already have a 70cc saw, I say use it for the times when you need a big bar, and get a 562 with a 20" bar off of that big online auction site. I got mine new a month or two ago for under $700 with the $35 hard case. I also ordered 2 loops of Stihl RM chain for $40 shipped, which was a great investment. This saw absolutely rips! Can't wait to buy the replacement for the 372xp after they are sorted out.