You have a message re the M50 1.7

This is a rather synthetic argument. Not all courses -- or teachers -- are equal. The best are inspirational and the best instil a level of discipline and perception that would otherwise be attainable, if at all, only over a much longer period. We can easily agree that some people are uniquely talented. That does not mean they cannot benefit at an early stage from some form of structured learning, even if they swiftly leave it behind. For many of the rest of us, I'd say the benefits of being inspired and learning from a well-run course, of whatever nature, are pretty self-evident.

If you haven't already seen it, you might find this link useful, a report on the photography course by a student who's taken it: http://www.thestudentroom.co.uk/showthread.php?t=2011496

The main caution seems to be that the course is very basic at the outset - fine if it's a first serious encounter with a camera, but otherwise perhaps a little frustrating

I'd go with that; on the other hand it's a mighty qualification. Let's see ...

Lack of hot shoe doesn't appear to have slowed sales of Sony's RX100.

Just to say that I put my lens through its paces last night in dim lighting at its longer end and had no real trouble. There were a couple of instances where it failed to lock, where contrast was negligible, but I think any of my lenses would have had the same problem (perhaps not if I upgraded to the K5II). Given Barrie's experience above, I'm aware my clean bill of health for the lens may be premature!

I generally use M or Av, generally centre-point focus, AF-S, and a mix of metering biases. I am intrigued by this discussion and will try to encourage mine to misbehave tonight -- while hoping it won't. It certainly hasn't in normal use. I don't recall ever failing to get a shot because the focus hadn't locked.

If my experiment shows I've been giving this lens too easy a ride, I'll post again!

I've never had the kit lens to compare, but my 17-70 rarely has a problem focusing, even in low light

The OP may have gathered by now what a finely balanced decision he has to make. It's odd that so much difference of opinion exists with so little persuasive evidence around, even though both versions of the camera are now 'out in the world'. It's also slightly odd to be hailing a technological advance that, if anything, is a 'rolling back' of technology. I don't doubt the veracity of the technical claims Pentax, and before them Nikon, have made for their 'e' or 's' cameras, but I'm sceptical that in daily use there's much of a difference. Possibly the marketing message has run ahead of reality (?). I think the fuss is largely generated because the K5II/s has comparatively little else to shout about (cf K7 v K5). This is not complaint or negativity, but observation.

The latest models of the K5 are good cameras. They have an improved low-light focusing ability compared to the original K5, so if you do a lot of low-light shooting you might appreciate that. I have not found the K5 deficient in that respect on a day-to-day basis; it depends how much low-light stuff you are likely to do. There has been a prolonged debate on another thread (as you'll be aware) about the benefits of removing the anti-aliasing filter. Suffice to say, that there is some benefit but probably not much for the purposes you describe. Compared with the bargain price of the K5, you will pay a premium of about £200 for getting a KII and about £350 for a KIIs. Only you can decide whether that's money we'll spent.