I've never used Martin tools, from the pictures they look to be of good quality.
Mostly I think Snap-On tools are overpriced, but it's hard to argue the quality and warranty. It's also a big plus when you work for a living to have the Snap-On truck roll through to warranty tools etc - rather than taking time off that you don't get paid for.
I only have a few Snap-On tools and their Body Hammers are top line IMHO...I've handled lot's of cheap hammers over the years, but when I was 18 years old I bought 3 Snap-On body hammers and 2 dollies. I used them full time for 8 years until I was 26. I still used them afterwards - just not to make a living...
Time - Warp
I'm 45 now and 2 of the 3 hammers and both dollies "grew legs" and walked away over the years.
The Snap-On BF604 hammer I have left has made me a lot of money, still has the original handle and I use it more today than I did 10 years ago
I am so sold on the quality of the Snap-On body hammers that 2 years ago I bought 6 more to fill my set out.
I hope to use these hammers another 20 years and I'd bet the old BF604 is still hammering away!
Pictured at left is the BF604 I bought when I was 18, the one on the right when I was 43
This is the Body Hammer drawer in my toolbox - nothing but Snap-On!