I've owned and used a 700rb and Neo 410 and they can get some serious volume. But, as with most GK amps the RBs lack a bit in the very low Qs. Consider that if your using a 5-string or down-tuning. The 4/5 switch may help you with that.
But its still a good choice, especially if you get that cab up off the floor about 24" or so. You'll lose some floor coupling but it'll put the speakers closer to your ears. (You do wear hearing protection, dont"you?)

I've not tried the Ampeg HLF 410s but I think they are considered to be better in the low end than GK cabs.
B.