I haven't had any experience with the Pros but you cannot go wrong with the classics. Dead silent and priming them(which you usually only do the first time) without a primer button is not that bad. My 2213 is so quiet that even a foot from it I cant tell if it is running or not.
Since the classics dont have the priming button, it's one less component to leak. I'd save the money and go with the classic.
I have both in my tanks and it's really hard to say which one is better. If I could do it again, I would buy the same combo, 2028 for the eheim installation kits and priming button and 2217 for quick dissconnects and lower price. You can check my journal to find how I configured my filters. 2217 is hooked with DIY reactor while 2028 has in-line heater and 2028 gives more flow. So my 2 cents are if you can find 2028 with installation kits and media in around $200, go for it.
I have a Pro 2 2028 Eheim in my 110g tank , It's a very good filter but?
IMO: I don't think 275gph is strong enough for my tank, I'm switching over to a Nu-Clear 533 & 547 w/Blue Line 55HD Pump w/2 returns all in a 1inch line system.
You would be better off getting 2 Pro 2 2028 Eheim filters or look into OC or NC canister filters witch I think would be better for large tank.
I would love to try a Pro 2, but I haven't been able to get over that price difference. I've bought a bunch of Classics and have had good luck with them. If you go with the Installation Set on the return it is very easy to prime.
The priming function on the Pro II are not as convenient as they describe and I haven't had to prime my 2213 as such. I just opened up the valves after packing the filter and it primed itself.
I also had the main gasket failure on my 2028 which is really annoying. It seems it's prevalent for the Pro II's. Now that I've tried the Classics, I think I'll continue to get them or the ECCO's. To get around the no baskets thing, I just bought filter bags. You can get a lot of extra stuff for that $100.