I'm sure this will generate some responses, but here's my .02.
SF2 is fantastic. Blufor definitely outclasses Redfor, but the challenge is often to win while taking no, or almost no casualties.
There's no APS here, so ATGM's are still scary. Now in BS anything in LOS is potentially dead as the lethality is max in that module, but the challenge in SF2 isn't far behind that.
One of the best things about SF2 is that there's a metric s*** ton of content. Scenarios, Campaigns, mods, and so on.
MOUT ops are so fun, stressful, and immersive and SF2 has them in spades.
Finally, as you said, the variety of equipment and nations is very appealing. Tooling around in British recon AFV's while trying not to die is great fun.