Lets face it... I've been diving for more than a decade now and just recently took the crazy plunge and opened a dive shop. In more than a decade and more than 1000 dives I have tried a few regulators.
My very first regulator... a gift from my wife was the Scubapro MK2 - R190 combination. I dove that for almost 6 years before I tried something else. Then in quick succession I tried something from Mares (it free flowed out of the box), then the Atomic B1 (it was like sucking air through a straw in the inverted position), the Apeks ATX50 (a quality regulator) and then back to Scubapro with the MK20 - G250, the MK16 S550, the MK25 -G250HP, and finally the MK11 S555.
In all this time I preached that I would dive nothing other than Scubapro after having tried the Mares, Atomic and Apeks. My favorite regulator from Scubapro is the MK16 S550 with the MK25 - G250HP being a close runner up.
Now for the Surprise... I have a new favorite... and one I never thought I'd have. Now don't get me wrong - I still own my Scubapro's and still love them... but there is a surprising alternative that competes readily...
The Cressi-sub Ellipse Alaska 1st and 2nd stage regulators. Both my partner and I have tried these things and we're believers. The fact that both Scubapro and Cress-sub are made in Italy should not go un-noticed. The comparisons should not stop there. Both are quality regulators.
What is interesting is that Cressi-sub regulators have never really caught on in the USA... but they do very well in Europe and in Africa. So America, it's time to wake up to a less expensive high quality alternative regulator. The best part... they can be had for much less than their Scubapro counterparts.
If I were recommending a regulator today... I'd tell you to buy one of the following... in no particular order:
Cressi-sub Ellipse Alaska
Scubapro MK25/G250HP
Scubapro MK16/S550
Scuabpro MK20/G250
While some will swear by Apeks regulators (and I did like mine well enough,) I can not find it in me to put them up to the Italian standards. Not knocking them at all... just my personal preferences.
If you're in Baltimore... take our Cressi-sub Ellipse Alaska challenge. We go to the quarry and swap regulators with you. You tell us what you think.