I will be doing the exhaust spacer instead of the DS. $60 vs $500 (plus shipping - 150?).
I would think yes - to an extent. You could run the 2.5" lift without the exhaust spacer or the DS swap... but as you flex (drop the axle) you'll slowly wear out the boot until it fails. Having busted my front DS on my 07, driving out, or trying to, sucks with only the rear and no lockers. I basically got pulled everywhere until we hit hard trail again.
I was never really interested in the 2.5". I love the look of a lifted jeep, and wanted the belly clearance. In this situation, it's purely based on looks. Sure there's a slim chance I'll go with 37s or something extreme in a few years... but mostly it's because I like the look. I'm vain, sue me.