I've got a Troy Bilt TB635 30cc head and all the Troy Bilt attachments. Can't recommend the TB635. One season under the belt and I've already replaced the carburetor. Wouldn't idle and ALL I EVER run in it is non-ethanol gas. Get a Stihl or something else. Since getting a (light weight) Black & Decker 40V electric trimmer, all I use the Troy Bilt for is edging because I need the torque only a gas burner can give. Love the grab and go convenience of the B & D.
I've gone to electric mostly but still have gas burner backups. Can't kill my 13 year old Craftsman lawn mower. The deck is showing some rust and wear but the Briggs engine is going good as new and starts on first pull ... with a clean air filter. That said, I sure do love LOVE the grab and go convenience of my new Kobalt 80V mower. Model KM 5080-06 just came out this spring and much improved over previous Kobalt 80V mower offerings. The Craftsman is relegated to mulching up small limbs twigs and leaves where I need the torque of a gas burner ... and the Cub Cadet comes in handy too ...
Oh, and the old Craftsman ...
... and just for grins and giggles, showing off my S.h.i.t.e. Shirt beside my old Snapper. After 25 years, it was still running pretty good when I gave it to a neighbor a few years ago. Dang Snapper would cut it if it could run over it and when adjusted, that dang Snapper could CLIMB !!!
EDIT: Someone told me if I want something that'll last 35 years, get a Toro. Heck, in 35 years I'll be 101 !!! ... I just want worry free convenient and fun.