Pros: Clear, neutral and engaging sound. Surprisingly capable headphone amp.
Cons: For the price? Not much!
Bought this to use on the go and couldn't be happier. I've compared it to both the Dragonfly and Hegel Super and I can say that it comfortably trumps both those. The Dragonfly is good but music from the Explorer seems a bit more easy going and natural in comparison. And the Hegel Super is sadly disqualified for having a very high noise floor, on high impedance headphones you can't hear it but on everything else a very audible hiss is present.
I've also compared the Explorer to my Anedio D1 stationary DAC, and for a $300 portable device it does exceedingly well. As one could expect there is a performance gap here, and in comparison the Explorer comes across as more "mid-fi" rather than "high-fi" in flavor, but that's not always a bad thing depending on what you're after. It wasn't that long ago that this level of performance cost three times as much and only came with a power cord, for a USB powered portable device it is seriously impressive.
I also tried to power my HD650's from the Explorer and was very pleasantly surprised, I've heard several wall powed headphone amps that have done far worse! For such a puny device it has a very impressive drive and bass definition. If I was shopping for a entry level headphone setup a Meridian Explorer and HD650 would definitely be on my short list! It is hard to understand how well this little device actually drives these headphone until you've heard it. I suspect they must have used the HD650 as one of the development headphones, the synergy is that good.
Meridian has a long standing reputation in the Hi-Fi industry and the Meridian Explorer has been recieving a lot of praise in the press lately, but I'm happy to report that in my opinion all of it is well deserved! The combination of price, performance and form factor is very attractive and as an audio upgrade for a travel laptop it's almost a no-brainer. In short, this little device rocks and I have no problems recommending it.