With all due respect, if you're not diving in very cold water, there's absolutely no benefit to a sealed reg. The only place "water gets into the reg" is the ambient chamber. It's a non-issue.

Here's my official advice, worth exactly what you paid for it (although I've been a certified technician for over twelve years, trained by most of the major manufacturers): if you're diving in water below 40°F, buy a Mark 17. If the water isn't that cold, get a Mark 25.

Or any of the Atomics, except for the T-2, which for some ridiculous reason, only comes sealed.