I absolutely love the HDX. It's the only add-on that I built myself that worked first time without debugging! (Thanks to the extremely well designed PCB and simple-as-dirt instructions. Super easy to follow.) I highly recommend it.
Spot on! Absolutely love this modification, it's rendered my reliance on floppy drives to almost zero.
But the best thing.... unlimited storage capacity!!!
Now, if we could encourage Fred Kaal to fix a couple of the bugs in the current version we'd be even more set and I'd raise my vote to 10/10 (from 9/10).
BTW: The major bug is when you try to copy files with special characters, it will fail, even when using the appropriate substitute (see the docs) characters. So, a small bug which isn't too bad but, can be annoying if your app insists on using special characters in the filenames.