I have been in that position as well. For insects such as butterflies and Dragonflies I personally think 100mm is the minimum focal length. 150mm or 180mm can be expensive. Alternatives are your 70-300 with an extension tube but it will be manual focus and manual exposure (depending on extension tube) or a teleconverter is pretty good on a 100mm macro as they are so sharp to start off with. Then of course the Raynox macro lens would work well on your Tamron ......
That hasn't helped has it! But you should consider everything and in the end it is the use that you want it for that should be the deciding factor.

Jolly good, another tick. Thanks for that.

Has anyone established definitively what the remote capabilities of the K30 are? Is it just IR on the front like the K-r or does it have a remote shutter socket?

I'm pretty sure the whole lot would be covered by your car insurance, especially if it was locked in the boot and not just in the car, although I guess the value may be above their maximum limit and then there is the excess but have a good look. Certain home insurances might cover it but don't raise your hopes on that one.

Yes, just a quick update. FIxed by Sigma via SRS with little stress and it is now a different and effective beast altogether.

I'm beginning to think that. The focusing seems a bit "snappier" as well.

Yes and Yes!

Does it have a proper remote wired connection socket? I imagine it does but these are the sort of things that get omitted to keep the price down.
It isn't obvious, on balance, why it would perform worse than the K5. I think if it remains cheaper than the K5 I will upgrade from my K-r once a few reviews confirm the IQ.

A lot of wildlife photographers around these days - what about camo? A 400mm lens wouldn't go amiss while they're at it