Halo Reach pace was slow as balls. The gameplay sucked and by adding "bloom" and random-ness, there was no skill gap and anyone could compete with anyone. TU 1 fixed that, but by then everyone was gone.
Well the kernel is too high for the JTAG hack. I don't know if RGH works on non-slim models. Or you could try one of the new products Team Xecuter has launched. Never used any of them though, so can't be of any assistance.
I'll build the new images tonight or tommorow. That will reboot you up to the newest console revision. Then, assuming we still have the patched files in place just try the game and hopefully it works.