Overall, this seems to be a very good supply, but it has a major problem with RF work, but first of all, the good stuff. <br />
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This supply really is a great supply to have around, the screens have a nice, bright backlight and the numbers are really sharp. Also, the knobs are not overly sensitive so its not that hard to dial in precise voltage values on the unit. Finally, you really cannot beat the price for how solid of a unit this seems to be.<br />
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Now, onto the problem with it. I was using this supply to do RF design work with ham radio. Nothing extreme, I was powering a small 5W 2m portable transmitter module with this supply and the transmitter was at least 4 feet away from the unit, but every time the transmitter kicked on, the supply would reset. Even my handheld 2m radio on low would cause this power supply to completely freak out and reset itself in a loop until I stopped transmitting. If I unplugged all wires expect the main AC cord and let the supply idle, it would be fine, but if I connected the wires to the DC out plugs, the wires would act like antennas and once again put the unit into a reboot loop. This power supply seems to overly sensitive to RF interference, even though the computers that run the USB scopes were not affected. If any of you plan on getting this unit for use in an area with any sort of somewhat high power RF work, move on and find a power supply with better RF shielding. I had to go back to my trusty lead acid battery due to this quark in the power supply.<br />
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What can I say though, this is a seemingly solidly built supply, with bright easily read screens, and a great price. It does have a fear of excess RF, but I dont imagine too many people are going to be using in a ham radio or other RF saturated environment. As long as you dont have RF issues, you wont regret this supply.

This seems like a decent power supply from the pictures, but I have to say, I'm a bit disappointed. Immediately after plugging it in and turning it on, I noticed that the Amp display had no reading. Not even 0.00 -- It was just blank. I figured maybe I needed to put a load on it to get it to display, but no such luck. The Amperage screen was DOA. (ok, DOAs happen. I can forgive this.)
The power supply itself still seemed to work fine. I could dial the Voltage up and down. Although the controls seem a little "twitchy" to me. (well, maybe "sensitive" is a better word.)
Since the dial is so sensitive, this power supply could really use is a "lock" button to prevent the voltage from changing if, say, your hand accidentally bumps the dial.
The part in all of this that bugs me is the Extech support/warranty. I contacted support via email, they determined that it was indeed bad. Then I was advised to call a number to get an RMA. The woman on the phone first said it would cost me $50 to repair. I said, "hold on. I just bought this thing." And she said, "oh, you need to send it back to the distributor if it is inside of the first 30 days." And I asked, "well, what if it was after 30 days?" she said, "oh we'd work something out." O_o
Quite a bugger as it will take 3 or 4 days to send back and another 3 or 4 to get a new one.

Why not just get some shielded leads to use? Sounds like the RF shielding on the unit is largely okay, you just need the connecting wires to be shielding so they don't act like antennas.
TheDeepFriedBoot:
What can I say though, this is a seemingly solidly built supply, with bright easily read screens, and a great price. It does have a fear of excess RF, but I dont imagine too many people are going to be using in a ham radio or other RF saturated environment. As long as you dont have RF issues, you wont regret this supply.