I really like the 550, in manitoba the snow doesnt get super deep (2-3+ feet) but the terrain will kill you. I find it plently good in the deep brush and had driven many times into thick bush ( willows, shrubs etc) without any real issues. The clutch engagement is very nice and smooth at lower rpms, I dont think it is as nice as the ace 600 from what i read but good nonetheless. I guess my overall evaluation is for larger guys like myself the 550 seems really better suited than the 300. I found the 300 struggled more and was more likely to dig itself into a deep trench. bear in mind I have much more experience driving the 550 vs the 300 .
I would agree the 300 wins on fuel economy and in very tight situations may be more nimble. I just have gotten used to driving my sled and the found that I can get it to turn in very tight quarters. That plus you need to be more careful by looking ahead and planning your route. I am sure with the old elans you just drove them and didnt really care how tight of a situation it was cause it always squeeked through. i remember with my old bearcat WT it was a tank and needed a football field to turn around so you were always very careful about picking your route and that cautionarty approach still sticks with me.