I just tried out a loop of Oregon LPX (chisel) on my Husqvarna 445; it was like a new saw. No problems so far running it on the POS microlite bar, but I bought a standard .050 bar and several loops of LPX that I'll switch to after I'm done with my test loop of LPX.
The LPX dulled a bit faster than the narrow kerf semi-chisel 95VP (aka H30), but the cutting efficiency more than made up for it. I sharpen my chain with each refueling anyways, the chisel just needs an extra stroke compared to the semi-chisel.
If even 1/4 of the wood you cut is fairly clean, get at least one loop of chisel (Oregon, Carlton, Stihl all make loops that fit your saw). The first time you put a chisel chain to wood you'll get a woody. Actually that happens to me every time. I was just out today cutting dead, dry White Ash with my 46 cc Husky, wood chips streaming behind me, the bar smoothly feeding itself through 10" diameter logs, I finished a few cuts and just started laughing. No saw to tiny should cut so well. Whereas I previously would have fired up my 066 for 12" logs, I'm now using my 445 on up to 14" logs.
On bar length I'd go with a 16" unless all you cut is softwood. Some prefer a longer bar because it saves them from bending over so much. I've found shorter bars are easier to keep out of the ground, and less likely to unintentionally hit stuff with the tip, but that's probably as much to do with my technique as the bar length.
