I own the Mastech 2108 and discovered that it is not as accurate or fast for measuring DC in-rush as I would prefer. For all other features it is spot on and a great value. When I bough this it was to replace a Fluke that I had loaned to my dad for over a year. The day I got it back I dropped it out of my pocket from the dinghy and into the water. Ouch!!!! Should have left it with my dad a little longer..
The Fluke 337 will accurately measure DC in-rush but the Mastech 2108 is not as fast. It works ok for AC in-rush but I do not believe it captures peaks as well as my old Fluke did for DC in-rush.
I do plan to buy another Fluke but have not been in a huge rush for these very short duration peaks as they have not been a huge priority recently. The Mastech has proven to be a decent meter though. For the price, the 2108 is an good value and a surprisingly durable meter. My only complaint other than the DC in-rush (does AC in-rush fine) is the size of the display numbers, too small..
I believe Extech makes a clamp that will do DC inrush that is as fast as the Fluke so you may want to check them out as well. I also own a UEI meter, though not clamp, and that meter has been beat on for years and years and still keeps ticking...
If you find a good deal on a Fluke 337 let me know, I need a new one. I still recommend the 2108, with the DC in-rush caveat and the small display peeve..
If I had to do it again though, for an in-expensive DC clamp, I might try the Extech EX 830 1000A AC/DC clamp, it has a built in infrared thermometer and will capture DC peaks greater than 1ms in duration (about $210.00) or the EX-730 which is an 800A AC/DC clamp that also captures DC peaks greater than 1ms and costs about $160.00.
Edited: I see Ed beat me to the EX-830 recommendation...