Hi,
Welcome to the site.
There have been a lot of good responses so far. I'll throw in my 2 cents worth.
Bottom line (for me): I'd recommend the
B2910 since your intended tasks are "most of the time" finish mowing and "occasional" FEL / brush hog work.
Disclaimer: I have no experience with the L-series Kubotas; most of what I think I know I've learned on this site.
The only comment that I don't agree with deals with the FEL/Mid-mower combination being a bad idea. The way that I understand it, in the 1970s, 1980s, and up to the mid 1990s, (basically the non-flat-deck model tractors), a person with a Kubota tractor that had both FEL and mid-mower may have had less ground clearance (compared to the mid-mower clearance with no FEL, which was poor to begin with). To my understanding, the flat-deck B-series Kubotas have no problem with the FEL / mid-mower combination.
For finish mowing and light-to-medium FEL work across a nice lawn, the
B2910 is probably your best bet. The way I understand it, the
B2910 will handle a 5' rear rotary mower.
For heavier FEL work and more extensive rotary mower work, the heavier L-series should be considered. However, I've heard somewhere that the mid-mower design on the L-series are not as good as the mid-mower design on the B-series, but I can't remember where I got that information. Since I don't know how accurate that information is, you might add it to your list of comparisons to evaluate.
Hope this helps,
Kelvin