I have found what Eastman is currently building to be about on par with Martin in the same price point. IMO, both brands have their pro's and con's. After owning about 8 Eastmans and a dozen Martin's over the last decade here is my take
Eastman Pros:
- Great build quality
- Great value for materials (woods, frets, finishes)
- Wide variety of options and availability
- Very stable in terms of humidity and temp changes
- Polished frets
- Handmade feel
- Lifetime warranty (they replaced and entire guitar for me for no charge and it was my fault for not keeping the humidity right)
Eastman Cons:
- Small fit and finish details. Not quite up to par with Martin's fit and finish
- Handmade guitars lend to some variance in actual build (neck shapes, nut width)
- Eastman has been known to try new woods, specs, finish etc, without letting the customer know (using different woods for the same model)
- resell value is not as good as Martin
- Doesn't sound like a Martin (has it's own sound. This could be a pro or a con depending on what you like)
Martin Pros:
- Name and brand recognition
- Has the consistent Martin tone
- Good resale value
- Pretty high level of fit and finish
- Guitars range from a few hundred to hundreds of thousands of dollars. There is a guitar for everyone.
- Has been an American guitar company which stayed in the same family since 1833. Lots of history here
- Literally invented the Dreadnaught and is considered to have made the best sounding acoustics in existence.
Martin Cons:
- Necks have come underset. High action and low saddles (Eastman is the opposite in most cases)
- Are usually a little more lightly built than Eastman, which makes Martins sound good but they are more susceptible to temp and humidity changes
- Most of what Martin is making now is not as handmade as Eastman (unless you are in the Authentic or custom shop price range)
- Martin warranty doesn't cover as much as it should, and is for just the original owner.
- I have personally had a few USA Martins that needed neck resests within 10 years, which makes owning the guitars a lot more expensive than my Eastmans. I have never had an Eastman in the last 10 years that needed more than a basic setup.
Again, both companies have their pros and cons. I say buy and play both!
Now as for an E10SS, I have never owned own. But I am about to get an E1SS and I will compare that to my D-18 and J-45 when it comes in.