Ahh nice you got to do the courses. I was going to do them just to have tickets but they're pretty bloody expensive!
I love being among trees is all really. Like deep in a forest feels special to me, I feel relaxed and happy with a massive sense of relief when among big tree's. So I love working with them purely more hobby than anything work or official wise.
391 and 550 I bought as do'er uppers and ended up working them. 435 was my actual saw but it's not big enough for the stuff I been doing. So I think a pro level 50cc saw will do most things I ever need and keep the 391 for big boy jobs...... I've never used anything bigger than a 491 other than a Husq 555 but they are both equiv saws really. Both top end "farm" level saws in the 60cc range.
I've done 6x cherries during lockdown for Jo's mum and dad. Every single one of them leaning ridiculously. 2 of them were horizontal coming over their property and directly hanging over their summer house and their oil tank so they were very difficult to do solo and with not much experience. But I done them all spot on. No injuries, no damage to anything and a nice clean solid job. So very happy. I now have about 2 winters worth of nice cherry for the stove as well which is airing nicely.
Done 2x 60ft poplars up on Jo's mates farm. The slightly larger of the 2 was 4ft through so we ran the 555 with 20" bar for that one. Biggest thing I've ever done yet but was straightforward.
440 is the most common mid range farm type saw so very likely you used that. It's just a step up from my 435 but is very well regarded as a general use strong enough saw for most jobs.
We have a brown bin here for garden waste but I can fill that within 2 hours working in my garden. So I would recommend a mulcher/shredder type like you mention. That's all I have really it's not a proper chipper but it is certainly good enough for personal/home owner type use. An Eliet is what I have but no idea what model it is and can't remember the size of wee Honda engine it has but it certainly does for me.
You're probably like me in the IT world Roady. It's nice to be sat at a desk most the time and not busting your ass. But can't take away that back to caveman enjoyment from things. Tom Moses from Madison Genesis finished up cycling last year and he's now climbing and working for an arborist company.