...what could it be? Less than stellar AF speed in low light? Lack of advanced video features? Known quality control issues?...

...Actually, none of the above. The K-5's Achilles heel is it's sup-par high ISO performance.

No, really. Go look. http://www.pcmag.com/article2/0,2817,2400556,00.asp

Proof if any were needed that certain (presumably paid) reviewers out there do not have the first clue what they're talking about.

Really excellent. Out of interest did you use a present manual focus or did you let the camera autofocus each shot?

Sorry to be the bearer of bad news, but you won't find an ultra-wide zoom with a max aperture of f/2.8 continuous. It doesn't exist (at least not in Pentax K-mount fit). The closest you are going to get is the Sigma 10-20mm f/3.5. If f/2.8 or better is the most important thing for you, you are going to have to settle for a prime, and even then your choice will be extremely limited. There is a Pentax 14mm and a Sigma 15mm which fit the bill, and I think that's about it.

As far as low-light performance goes, have you tried pushing your ISO up a little higher? I believe the K-r performs quite well in this respect. It should certainly be adequate for restaurant lighting.

Look at it this way, the difference between f/3.5 and f/2.8 is only two thirds of a stop. Pushing your ISO two thirds of a stop higher should really not present a huge problem.

As a tabletop role-playing gamer (my other hobby) this comment is vaguely amusing to me. It's an industry so fraught with difficulties that specialist retailers regularly close their doors and hobby magazines regularly go out of print even when the economy is booming, and the last major high street retail stores (Virgin Megastores) to stock hobby related materials quit the market years ago. In comparison, it makes photography look like the height of mainstream popular culture.

I for one don't like large, heavy camera equipment. I like that I can lug around what seems like an ungodly amount of high quality camera gear (including 5 lenses and a Metz 58 flash) and my camera bag still only weighs about 5.5 Kilos. I can't see myself ever going full frame, certainly not as long as I'm 'just' a hobbyist.

Why would a sweet-smelling bunch of roses make friends with a pile of stinky rubbish?

Fine, as long as I come out of it smelling of roses and you look like a pile of stinky rubbish.

No. This particular thread of the conversation was begun my reply to johnriley's post. Not your's. John's. The previous thread of conversation was OVER as far as I was concerned. Go look. John's post, not yours.

You took exception to my telling people to relax. That was said in a reply to John's post. It had nothing to do with our previous exchanges. I'm just trying to make this as clear as darn possible.

You cannot change the subject matter of my post to being about you when it wasn't about you in the first place. It doesn't work. Subject matter doesn't magically transform itself into something else because a particular person replies to it. Seriously, if you think the world works this way you cannot possibly avoid taking everything anybody says to you personally, all of the time.

Clearly I'm not the one going of the deep end. And don't come back with some sarky comment about how I was leaving the thread. I won't let you just distort it in this way. I'm too stubborn. My failing.

In fact, no really, explain this to me. Since my original comments weren't directed specifically at you, how would it make even vague sense for my response to your response to be directed at you. Just because you replied to my post, it doesn't change the subject matter to yourself. The subject matter is still the same as in the original post, nothing has happened to magically transform it. I can't even grasp the leap of logic this requires.

Sorry, but I'll take your advice on one thing. I'm out of here.

If you want an oxymoron, here's one. I ask you to explain yourself and then say I'm out of the thread. Job done. Seriously, I'm confounded that you could possibly take anything I said personally given that the context had nothing to do with you in the first place.

Are you serious? You need to lie down, fella.