I'm an owner of a MiniMe and it sounds great. The USB option is a plus. I've never used it. But if I ever need it, it's there.
A mobile pre/converter with S/PDIF only would be pointless. How many laptops have S/PDIF in and out? PCMCIA S/PDIF cards are (or atleast were) pricey, and many laptops these days don't support PCMCIA. So if it didn't have a USB/Firewire port you would have to carry around another USB/Firewire card with S/PDIF on it.
I would rather have USB than Firewire... 2 audio channels don't get near maxing out USB's bandwidth and more current laptops/desktops have USB than Firewire.
I also still consider the USB option a "bonus". If I ever need/want to record something remotely, I'm set. Even if the sound quality wasn't as outstanding as it's S/PDIF out, it would probably be more than enough for the job, in probably an untreated/less than ideal place. The non-existant limitations the USB interface was causing would be the very last thing on my mind in that situation.
I have not tried the MH product, but the MiniMe is top notch for what it does... The Metric Halo dilly might sound great as well, but don't buy into the only thing you get with the MiniMe is the Apogee name! You get 20 years of excelence and a major reputation at stake. Quality parts and a great design. Add it up and you get great sound.
If the MiniMe didn't sound good, it would be big news. A lot of people have shot it down based on nothing but negative vibe. If there was any substance to these claims it'd be everywhere.
I wouldn't have bought mine but I got an outstanding deal on it. I'm super glad I did. I can't get over how great it sounds.
The exterior design quality is shit for a "professional mobile device". But it's built well enough to survive my unmoving rack.
I think it's ironic that pro audio devices with digital components in them get labeled shit in comparison to another product. But all analog products come in "different flavors".
There is nothing wrong with these converters or the USB interface for the purpose of this product, IMHO.
I think the compression curves are a great addition as well, they add color to the otherwise lush transparent sound. They also add more versatility to the product. There is no audio out (besides the 1/8th jack diled to "DIR(ect)".
No complaints here.