i'm running the F112 with on-board x-over set at 80 and my mains (era d14's - solid down to the high 30's) on "Large" blend is good with no issues. electronics are pioneer SC07. I have tried both sc07 xover as well as the JL and did not notice any differences. I'd suggest trying the onboard and if you find that lacking see if you can borrow or sample a external unit before you buy. I've also run the JL crossed over higher (>120) and it still sounded great. someplace it should have issues but I don't know where.
