Light profile if you're going to be doing 'tactical stuff'. The weight difference is noticeable. Adding another #+ via a can is going to make an already heavy gun heavier (obviously).
Keymod is going away. I prefer the thinner profile and much more positive engagement of the accessories....but the industry and RA are going away from it due to customer demand (largely due to Crane tests which don't really apply to the XCR since it's a much thicker handguard than AR configurations). KM is only a few ounces lighter...the bbl difference is a much larger percentage of weight. RA won't even make the new "mid length" Garand Thumb handguard in KM; already asked.
I have both mini Ms and standard. All depends on personal preference and weight savings. The Mini is obviously lighter.
I prefer the Type 3 b/c there's more adjustment and is IMO a better design.....I have the Type 2 on my 16" HBAR. Nothing wrong with it....it's just a bulkier system and isn't as simple in terms of design.