ESEE and swamp rat are my two favorite brands and I have alot of experience with both, especially with the RMD. You can't go wrong with either company.
First in terms of design when comparing the ESEE 5 to the RMD they are completely different designs but are pretty similar in size but not weight. The 5 is very heavy and does not slice well while the Ratmandu is thinner, lighter, faster and much more nimble in hand. For anything woods related i think the RMD is just a better knife. The 5 was designed for pilots to cut their way out of downed aircraft. The 5 is a beast of a blade but is extremely heavy for its size and its weight does not give it more ability.
A much fairer comparison is the ESEE 6 and RMD. Both of which I have and think very highly of. The 6 is bigger, has more cutting edge and has a wider blade. It is also heavier and chops much better than the RMD especially with the extra handle length. The RMD is better for bushcraft because of the shorter blade. It just feels alot more nimble in hand than the 6. So the 6 is better at bigger tasks like chopping and batoning and the RMD is better at finer ones like carving, skinning etc...
I may be biased but after lots and lots of use the RMD is my all time favorite blade. It feels like magic in hand and has a wonderful choil. THE most comfortable knife Ive ever used. You have to feel it to understand.
In terms of steel, SR 101 is a better steel than 1095 with any heat treat can ever be. 1095 is an awesome steel that is tough and holds a really good edge but through all of my usage SR101 continues to hold a better edge and though Im not sure it can be proven, I personally believe SR101 is a tougher steel than 1095. And this is not to say anything bad about Rowen's 1095, its really great stuff but Ive done head to head chopper comparisons with my Rat Daddy and Junglas and the Rat daddy will continue to shave long after the Junglas has stopped.
I think price is going to be the issue you want to look at. You will probably end up spending at least 60 more for an RMD and sheath than you would an ESEE 6. You can get an ESEE 6 and sheath for maybe $115 at any given time but an RMD is going to run you much more and doesn't come with a sheath.
Again you honestly can't go wrong with either. Another thing to consider though is that ESEE's ALWAYS come with a better factory edge than Swamp Rats. You may have to do some reprofiling to really get the RMD to cut well while anything ESEE has an awesome factory edge that doesn't need any work.
And just so you feel confidant in your choice, out of all the medium sized blades Ive ever owned the RMD is my favorite and the ESEE 6 is a close second

If you have the funds buy both!
Ill put up some comparison pics for you. one sec.