I wrote a previous review of an Eb Mars where I docked it for not playing well out of the box, specifically hole 10. However, after taking it apart and tinkering with it a bit, I got hole 10 working fine. Then, a bit to my surprise actually, I found myself playing it more and more.
Since my playing is focused more on jazz than blues, I wanted an ET tuned harp that wasn't going to break the bank and would be good as I move through my studies toward the intermediate realm. I'm a jazz bassist in term of background, so I know theory, but getting the harmonica under control in terms of physical execution of ideas is obviously going to take time.
I have a Hohner Golden Melody and it's expensive, a bit loud for me, and the tone can be a bit harsh on my ears since I have a bit of tinnitus from my youthful rock days. I find the Mars to be mellower and warmer, although a bit metallic at time -- but the covers and a good, tight cup seem to offset that. I also have small hands and this harp fits extremely well into my hand. It's just so comfortable to hold and play. I have a Bb Mars and a Bb Hohner Marine Band Deluxe, and I find myself playing the Mars a lot more than the MB. The round holes are great. I haven't tried the upgraded model with the aluminum mouth plate, but the plastic mouth plate is fine for me for now. I'm really using these to learn.
I'm tempted to dock this one star because, well, it's a $30 harp and so it does require some setup out of the box. But it's a $30 harp so, you really are getting great value. I'd say this is more of a four-and-a-half star review at the end of they day.
The low G (1 draw) on my brand new Low F harp is super out of tune and sounds awful. I have to tune it myself, which isn't a big deal, but is annoying for a brand new harp.
I would imagine that if I get better at setups, getting the $50 model with the aluminum mouth plate, and then flattening and sanding the reed plate, fine tuning and then shaping and gapping the reeds would yield a really awesome harp for $50 a pop plus time and effort. The great thing about the Mars is that, for $30 a harp (actually $29... I bought a Low F, a Bb and an Ab, all ET) I would be fine using them to as guinea pigs for setups. If I accidentally kill one I won't cry as much as if I killed a $65 Hohner.
If I can get the Low F in tune, which I think should be fine, then I'll be super happy and probably buy a few more of these down the road.
For a student player like me who wants an ET harp for a reasonable price, these are just awesome. Not perfect, but great for me.