32mm Boxxer user and fan here, mostly for budgetary reasons though…
I only use them for DH; mine are a 170mm travel, mish-mash of parts which could be called 04 teams, if you can get some 02 cherry reds for £150 then buy them, they seem to go for as much as double that though, mainly because they are talked up as one of the best DH forks ever and probably because they are far blingier, you'll make a profit if you flip em on…
Boxxers are DH forks and as already stated, pretty **** for most other things, set up properly they are relatively soft and a nightmare to climb with, but that’s not what a DH fork is for…
In terms of stiffness, they are on a par with any 32mm stanchion/20mm bolt through fork, pikes, various Bombers etc, stiffer than a QR fork with the inherent flex of 32mm legs which despite what some say isn’t bad at all…
Spares are cheap and moderately plentiful as they are now deeply unfashionable (except for the 02 model) and there are plenty of people who break them and flog them for spares (although the breakages should tell you something)…
If it’s for AM/allround use then forget Boxxers with the exception of the 05/06 Boxxer “ride”; the relatively rare U-turn model (125-170mm) which is an option but probably a good long way behind more current forks, if you can find one of the U-turn Domains they weigh about the same as a Boxxer (not that, that is light) but have the obvious advantage of being Single crown, with larger stanchions and a bit newer, other 2nd hand options might be Pikes or maybe one of the Marz’ 150mm AM offerings if you can find them…