I've owned a number of High Powers over the years, my current one (a keeper, not to be replaced) is a Mk III (I'm pretty sure) which is "Made in Belgium, Assembled in Portugal." It is a fine weapon, excellent fit and finish, completely reliable (over the two or three years I've owned it, no failures or jams of any sort), and has adjustable sights, which I prefer. As to quality, I find it to equal or exceed the quality of most of the Belgium made High Powers I have owned, with the exception of a Renaissance High Power (of course, that fancy gun never was shot). There were only two things I didn't like about it - the mag disconnect and its impact on trigger pull, and the ugly plastic/nylon factory grips. Both are easily remedied. Removal of the mag disconnector from the trigger assembly (or fixing it in place, but inoperable, actually a bit better from the standpoint of over-travel) is, generally, easily accomplished, although getting the trigger pin out of the frame on some of the late production guns can be a bear. The grip situation was remedied by the purchase of a set of checkered Cocobolo grips by Herrett (CDNN has a great price on them), which fit my hand a whole lot better, and are absolutely beautiful, as a bonus.
I recommend going for the gun, I've had excellent experience with mine. Oh yes, one other thing. I also recommend obtaining several Mec-Gar magazines for the gun. I have several Mec-Gars, as well as some factory mags (actually, Mec-Gar made most of the Browning HP mags), ranging from stock 13 rounders to extended 20 rounders, all have been completely reliable, and the price is right. Most recommend staying away from the Argentine 15/17 round mags, with a lot of reports of poor reliability - cheaper, but not many good reviews.