Agreed, especially for 1.5"+ dia wood.
Most definitely, and you can get 9" chainsaw-cutter blades for $15 from Forester. Total no-brainer.
For mostly smaller-stuff, I might use a 20-tooth 10" carbide (got a few to use up, can't sharpen-no diamond wheel), or 11" or 12" Husqvarna steel blades. Those 3- or 4-knife Husqy blades are DANGEROUS to woody stems up to 1.5", made of some tough steel such that I had to buy a 4" angle grinder to put an initial edge on them. Damn lawyers! Once they have a proper edge, most touch-ups can be managed w/flat-bastard.
I put lots of hours of use on all the above, using 21-27 cc brushcutters, clearing many acres of multiflora/privet/barberry/euonymus/porcelain berry and other rank invasives. They end up pureed on the ground for mulch.
Used to use those 80-tooth steel blades back in the day, like for woodlot mgmt. Only other choice was 8-knife blades, like for grass. Currently available blades give you lots more options, and hugely better performance, IMO.
For best pricing, consult Amazon or Forester. Dealer if time presses. Of course, Spike60 gives great prices too.