My personal preference is a monocore baffle. Modularity may sound like a nifty idea, but it's not for me; I wouldn't carry with a suppressor, so it's range/hunting only. And I do have an Octane, and I find lining up the baffles is a small PITA.. As is cleaning them really well...
I have 2 sparrows... They have FRP, BUT, if you are using subsonic (standard velocity) ammo, it's really not that bad.... You can get around that by using gel, or whatever, but I don't...