I have two of the 525s and they are great, I wouldn't ever buy any of the cheaper faucets now, especially after using the Perlicks for a while.
I could be wrong but I think they both are pretty much the same internally, they both have the forward seal... way better, more sanitary than the others. If you take apart your 525 you'll see how simple it is to clean when needed... prolly already have, right? I run Straight A through mine after each keg and I have never noticed my tips getting funky, although it might be nice to be able to unscrew them if I wanted to.
You'll be happy with ether one I'm sure, but if you have to get several of them the extra $ for the 425s might add up.
Kegged: BCS American Pale Ale, Blonde Ale
Primary: BCS American Pale Ale
Bottled: Janet's Brown Ale, Dry Stout, Irish Red Ale, Apfelwein
Gone:American Pale Ale, Irish Red Ale, Dry Stout, West Coast Red
Long Gone: Too much