I run both a Powertilt and a Hardford Prolock. Combined as one unit I should think they'd be very nice to use.
My main concern would be constant loss of breakout force- it's a deep stack height. I reckon I have best of both worlds- mounting the Powertilt under the Prolock. Yes, it's even more stack height, but I only scratch around with it, then take it straight off for digging, ripping or grab work. I always say that I'm so happy to put my Powertilt on to save time- and then equally happy to take it off again to save time on a different job!
The model Olly posted looks like it would go a long way to reducing stack height (especially on S30) but it simply wouldn't be enough tilt for me. However, it's a low build height, and if you are only trying to stay level without screwing round and putting the blade down, it's got to be worth a look.