I've had one for a year. However, I don't have experience with other devices for comparison. I use it with a Sennheiser ME67.
You have to use class 6 SD cards, otherwise it'll hiccup.
Using rechargeable batteries, I go about 4 hours before I put in a fresh set. I don't think this is ~supposed~ to happen, but the first time the batteries ran out while actively recording, the file in progress was corrupted. I recovered the file, minus the very end, using a copy-paste feature on the unit itself; so no harm, no foul. So, I never push the batteries after that.
I use it under rather "vanilla" conditions... no wet or sub-freezing conditions. It won't be water/rain proof. I'm gentle, so durability isn't tested.
The recording timer (set start time by calendar + clock, and set hour/min duration) is great for night migration. However, it does not record at *low* enough quality to seamlessly use with the (admittedly old) OldBird tools. I use a workaround to lower the quality.
I like the display. I think the interface is good. The bevel with the recording levels is ~okay~. Instead, I set the main display to show recording levels. I find it easier to see in bright light than the bevel.
Built-in speakers are enough for personal listening, but do not project.
The rec/pause/stop buttons are a good size. The Record button has a raised rim for tactile feedback, so can be operated without looking.
It's gotten the job done for me.