Ahh, but you are forgetting:
- HD500 has sharc dsp optimised for audio transformation rather than a general purpose CPU so is potentially orders of magnitude better at IR processing
- This IR suggestion will replace at least the Cab and Mic simulations which might already be IR based
The thing is we don't know whether the HD500 uses IR + Convolution or something else entirely, and those who do know either won't or can't say. So pretty much from the release of the HD series people have been saying "We want user IRs" and in all that time Line 6 have said nothing at all.