Having worked for Seal for most of my career, we came out with hand crank systems simply to take a ton of cost out. At first, I wasn't a fan...but you can really fine-tune the pressure which is nice...After a few weeks of using one, I was pretty sold. The drawback is it is very difficult to reset the nip if the rollers get out of parallel.
I've stated a few times on this forum that the last place you want to be cheap on is with a laminator. If you buy the right one, you'll use it for 10-20 years. It will far outlast anything in your shop other than a Gerber Edge. There's nothing more unproductive than screwing a print up at the last stage in your shop. GFP machines are solid, but they don't last as long as Kala or Seal units do (or if you really want to spend a lot of money, an AGL).