Harp SF isn't the most clear product (I found myself confused at several spots, though typically the confusion cleared when the point of ambiguity was cleared up later), but it's still very well written.
It uses a nice system with enough precision to be playable, but not so much that it's over-encumbering (though 80 skills is a mixed bag: versatile, yes, but also a little much, though admittedly these can be fine-tuned on a per-campaign/game basis).
The Fumble and Critical Tables were a nice touch, it's been a while since I've seen detailed critical charts, rather than just a "Take double damage and have something cute happen". I mean, it's not perfect, and I feel like at times you could run into places where they weren't applicable, but they'd be a stretch.
I like it, it's a decent break from the average, the art is good, the setting is decent, the price is not the cheapest, but you do get a coherent, well done product with enough content to be worth it.
[4 of 5 Stars!]