Although I can't compare it to the PE-2 as I haven't used one, I own a Raytek ST20 and wouldn't trade it for the world.
The reasons I love it:
1. Retains temperature (and Max) for several seconds after releasing the button...so I can reach into a box, squeeze the trigger, let go, remove it and see what the temp is.
2. Backlit
3. 16:1 D:S ratio (twice that of any PE gun)...this means a VERY precise measurement.
4. Laser (most have this...but I wouldn't buy one without it)
5. It's small enough so that I can fit it into the places I want, yet large enough so I don't lose it!
6. HUGE temp range...-25º to 999ºF (i use it for cooking as well)
Cost: Ebay $95 plus shipping (recently they're going for ~$100-140)