It seems a sensible strategy. Pentax has always been best-regarded for its DSLRs. Its compact cameras have rarely seemed to measure up to the best equivalents available elsewhere.

There's very little in it,or rather what there is could be explained by the slightly different aspect and lighting. Maybe we'd see differences on an A2 print.

There are so many possibilities in Berlin, the difficulty is in making the selection. Next time you go, if you are again shooting at night, the suggestion of human activity will give you an additional dimension to play with, even if it's only in the coloured streaks of passing car, tram, or train lights. Much of the S-Bahn in the centre runs raised above ground level, so 'lights in the sky' as well as on the ground can be effective. And if you want some of the 'stock' pictures of Berlin, you might experiment with unusual perspectives or angles, which would refresh even such much photographed places as the Brandenburg gate and the Sony Centre.

vielen Glueck!

This might (or might not) be persuasive at essay length ... but as it stands it's long on assertion and short on evidence. Again, I'd question your opening statement: 'the brand of equipment Pros use often influences a client's choice when hiring pros'. Where does such an unlikely notion come from?

These are separate points. In the first, in your original post, you suggested that clients' perceptions influenced the choice of equipment, which seems largely untrue.

In the second, you (more plausibly) appear to be suggesting that photographers buy equipment that will be regarded as of 'professional' standard by their peers.

I'm not clear what part you believe capitalism plays in all of this, but (whatever its sins) it does produce an element of choice, preferable to the outcomes available in a command economy.

Possibly ... but many (most?) clients would have great trouble differentiating between different camera models beyond the level of point-and-squirt

The D610 is claimed to have an improved white balance so s a test repeated using the K3 and D610 might flatter the former less, in terms of colour/appearance -- which is not to demean the K3's performance at all. It is impressive. But sticking roughly the same number of pixels (give or take a few) on a much smaller sensor suggests that more noise is inevitable, short of a cunning software suppressant, and likely to be less good than the K5's. The pics above bear out expectations.

Out of interest, in which respects would Pentax need to change/improve its cameras to match or surpass the one you have been so impressed by?

I like my K5 for many of the reasons already rehearsed in this thread (and like the sound of the K3), which is just as well since the thought of selling everything Pentax and restarting from scratch fills me with (inertia-induced?) dismay.

Cameras will continue to improve, but it is hard to see that in recent years the improvements in the final images they produce are other than incremental. Useful but incremental. So until the next revolution that upends the digital age (bio-cameras?), I'll likely stick with Pentax ... provided of course they continue to produce good cameras.

First shot is powerful. I love it. Third shot, too, is pleasing - and its second incarnation not only shows a straight horizon but also a touch more contrast, which improves it.

Spot on. Very nice.