I have an '06 Poprad, so I thought I'd weigh in on this. It's true that you don't see too many people talking about this bike. I'm pretty sure that the main difference between my bike and the newer model is that I have canti brakes, not discs. I prefer cantis and you prefer discs, so that works out well. I live in Edmonton, Alberta, and we have two hills here, so I don't mind a little less stopping power.

I use it for pretty similar purposes as the OP, but I have a longer commute (12 km/7.5 mi). It is a pretty flexible bike. Most of the time I have 28mm road slicks on it, but when I put the knobbies on there, it holds the trail really well. There is plenty of space for fenders, and I do have some that I put on sometimes. I have also put racks and panniers on it, though I did have to monkey around a little to get the racks on without proper braze-ons. I have done one overnight trip carrying camping gear. It worked pretty well for that, and I was comfortable for the whole trip. Well, comfortable except for the heavy rain, but I can hardly blame the bike for that.

I have never been on a Surly, and since reading so many raves, I'd like to try one. I'm still more than happy with the Poprad. It fits me well, and feels like an extension of my body, which is about all you can ask from a bike, no? I guess bottom line is that the Poprad is a pretty sexy machine and it can take a fair bit of abuse. Just make sure the bike fits you properly, and you'll be happy.