Well if we are looking at best all around reg's we have to look at a few considerations:
Ease of Breathing
Servicing
Cost
Diving Environment
Mares Abyss would be the "Best" choice. While its not the best regulator for technical, for recreational diving it is the best all around reg.
It breaths better than any of the typical recreational regs (Oceanic, Sherwood, Dacor, Genesis, USD)
Its better in Coldwater than Genesis, USD, Oceanic and equal to Sherwood.
Its got a lifetime warranty, parts are cheap, while it pails in comparison in Performance to the S600 the average recreational diver won't spend the $$ The Abyss is $300.00cdn less than the MK25/S600.
If you want the BEST performing regulator in the Industry you'll get the Scubapro MK25/S600.
The Oceanic is a good all around reg. The Zeagle (in Canada) parts are harder to get, and its not as nice a performer as the SCubapro or Mares.
So does a recreational diver who isn't going tech need the best??
If a reg that normally wouldn't configure for technical hose routing isn't needed is that a problem??
If they aren't diving in contaminated water is a drysealed first stage an issue??
The Abyss is the Best all around reg for the $$. The other option would be to buy the MK16/S550 from Scubapro which has the same first stage configuration as the Zeagle, lighter 2nd stage, breaths better than any reg's listed here, has a drysealed first stage, and is great for ice diving.
Good luck!