We've installed a couple of Hopper 1's for new customers recently coming from cable or DirecTV and all have remarked how much nicer the Hopper 1 is than their previous DVR. Its all relative.
Then there must be something different about how the new software is performing on a clean H1 versus one that has been in use for a number of years. It's lagging badly on mine, but perhaps it's not just CPU/RAM that's causing the lag, but instead something wrong with the particular install on my machine, or perhaps it's the 1.75 TB of content stored on it that the new software is less efficient about indexing.
If I had lots of time to kill, I'd transfer all the shows off of it, do a factory reset, and see what happens. But I don't. If I'm going to go through all that, I'll just bite the bullet and get an H3 (which I am).