The Mudmaster is great, I own 3 of them. It is a quality G, no doubt. However, the D1000 Frogman is a step above, IMO.
Keep your Frogman. You'd be taking a (small) step backwards by going for the Mudmaster instead. ;-)
That's my initial thought. Buuuuuuuut........unless you are a diver, all of the special features of the D1000 Frog are not very useful. I'm not a diver, but to me the D1000 is special due to its quality materials and construction, and appearance. The Mudmaster adds the altimeter, and barometer, that the Frog does not have. When I wear the MM, I make use of the Baro frequently - at least the baro graph. And aside from functions, the MM is a beautiful watch as well, and the dial (to me) is more interesting than the Frog's due to its depth and design.
The MM does have a sapphire crystal, like the Frog. The Frog's strap is nicer, being carbon fiber. As we know the Frog's case is SS, unlike how the MM is constructed. And maybe important to some folks, the Frog is likely to be at least somewhat tougher/more reliable given its all-digital nature vs. the MM's ana-digi movement.
I can see where it could be a tough decision. If I had to own only one, it would probably still be the Frog, even though its functions are slightly less useful to me than those of the MM. ;-) The Frog just has such an outstanding design and build, not to mention awesome look, that I can't ignore it. :think::-d