Slowly but surely, I am making improvements to a 32 acre place, 20 acres of which are wooded with lots of larger trees. I have used my TC45DA to move material, skid logs, clear brush, grade new roadways, maintain existing roads, etc. I do not believe I would have been nearly as happy tackling these projects with anything smaller than the 45 with 16A loader and 759C backhoe.
On the other hand, the 45 (especially with filled tires) seems entirely unsuited for anything approaching finish mowing. I hate to use it in the areas that get mowed to a low height (even the native grass areas) because the R-4s leave too much of a mess if there is any moisture at all in the ground. I am also not comfortable taking the 45 over some of the slopes I have to get at the grass that I would like to cut every so often.
Luckily, at the last minute, I decided to delay my purchase of a mowing/cutting attachment until sometime after the 45 was delivered last year. Now I am focusing on purchasing a dedicated riding mower of some sort, particularly one with a cutting width of at least 5'. It may go a bit slower than if I used the 45 with a 6' or 7' attachment, but I'll avoid the ruts and get alot more of the sloped areas too.
With what I know now, I believe that it is extremely difficult to find a single machine that you enjoy mowing with and doing significant other projects with. If forced to choose one, I would get the smallest, lightest tractor/loader possible and plan to hire folks to do the jobs that the small tractor simply can't handle. Others may have had better luck mowing with Class II or Class III CUTs, but it is impractical at my place.