I got the new pump that PSC sent me installed. This one works great compared to the last one; It moves those 37" Iroks with ease at idle. The new pump they sent me is made of steel and the one I was having problems with was aluminum.
Anyway, to the op; If you are having any problems with vehicle control at highway speeds, hydro assist will magnify it. My steering / geometry was 100% dialed in before hydro was installed. I had no bump steer, no drifting, and no wobble. The only thing I had was a very slight pull to the right when mashing the brakes. After hydro assist was installed, that slight pull when braking hard became a huge pull to the right any time I would brake - so I bled my lines and got the problem sorted out. Point being, your steering will be very touchy when the RPMs are up, and even a small existing problem with your steering could be very dangerous with hydro.
To give you a good comparison to what hydro assist feel like on the road to me; I drove on 37s for about a month with no steering stabilizer, and although I was forced to make slight steering corrections while driving, it wasn't that bad once I got used to it. Hydro assist feels the same way to me, like driving with no steering stabilizer.
The good part is that it turns very easy at a stop, and the control while climbing things in 4WD is amazing. There were many very tough lines I could not take before because I had no steering ability, but I don't think that will be a problem now. One of the other off-road benefits of hydro assist, is that is takes a great deal of stress off of steering components.
IMO, nothing wrong with hydro assist, but get your other steering issues squared away first. Honestly, if I did not wheel often and do a lot of tough trails - hydro assist would have been a waste of money.