The K-01's differences to a DSLR are well known, but to recap you're essentially getting a K-5 minus the optical viewfinder, second control wheel and WR sealing. The sensor offers the same resolution, the firmware and processors have been slightly updated. Thanks to the lack of a mirror it's even more essential that you switch it off before changing lenses, as when it's switched on the shutter is open and the sensor exposed.

The more strident reviews on a well-known video site complain about the size of the camera, and yes, it's bigger than most mirrorless interchangeable lens systems. But that's mostly because it has to be in order to maintain the registration distance, which enables the use of all K lenses. Unlike competing products which either need an adaptor or a completely new lens collection you can swap lenses between this and your K mount DSLR.

Other complaints concern the rubber flap over the SD card and ports on the grip side of the camera. It isn't that hard to operate and providing that you're gentle with it I don't see it failing in a hurry. If you look closely the rubber part doesn't really need to bend much, and it fits back into place pretty easily with gentle finger pressure.

On to the good points. The control dials, strap lugs, power switch and flash housing are all metal. Other buttons are plastic and feel much the same as any current Pentax DSLR. The whole thing feels well made with no creaks or odd noises when handled. Both the camera and the 40mm lens have metal mounts, the lens also has a neat push-fit rubber cap which doesn't seem as though it'll fall out accidentally.

The handling has come in for some criticism too. It is different to a DSLR, being more like an overgrown compact. My only complaint is that the green and red buttons should have swapped places on the top plate, as you need to either swap hands or press it with your left hand in order to meter with older lenses. It feels rather like a thicker MX or K2 in terms of the weight and shape. Essentially, if you've got a Pentax DSLR you will be able to find your way around this without much trouble.

Image quality appears as good as you'd expect, given the ancestry. The mode dial has HDR and SCN settings, I wouldn't have minded seeing the former on the K-5 as it can be useful to expand the dynamic range. It's a very subtle HDR rather than the argh-my-eyeballs effect often seen online - think of it as approaching the dynamic range of print film rather than slides. The digital filters and "scene" effects are pretty much unchanged from other models.

Lens choice may make or break this. Certainly I wouldn't have wanted one with the 18-55mm zoom, and it's best suited to smaller primes. If you have a collection of FA or DA Ltds you'll love it, if your collection is mostly zooms then you may want to look for some primes to go with it. I'm probably going to hunt for an FA28 when my finances recover. Remember, as it can share with your DSLR any lenses you buy will have more than one use.

Which leads us neatly onto another very useful feature named Focus Peaking. When activated this places a white outline around those parts of the subject which are in focus, making it easy to use manual lenses. I spent some time with an M 135mm to test both this feature and how it handles exposure with older lenses. In short, it does very well. If you have a few of the smaller A series primes they'll be superb with this camera.

The green and red buttons can be programmed via the menu system. As delivered, the green button does exactly the same as on any Pentax DSLR while the red button switches to video recording. As I seldom use video (and would find it annoying if I accidentally pressed it) I swapped this to activate focus peaking.

AF performance is surprisingly capable. I had read complaints about the contrast detection-based system struggling, but with the V1.03 firmware update it seems fine. I suspect the K-5 would struggle in the conditions which gave it some difficulty. Don't expect ultra-fast AF, but it locks on in a timely and reliable fashion. So far I have tried the kit 40mm, an F 35-70mm, and the M 135mm. As may be expected AF in low light is more reliable with faster lenses. I will shortly be trying the Sigma 150-500mm on a tripod to see how it handles 3rd party lenses.

I've posted a few shots of the camera next to a K-7 and also a few test shots taken with the camera here, all of these shots were taken with the 40mm lens with the mono one using the relevant digital filter. I'm still getting used to the new angles that constant live view permits, having hardly ever used it on the K-5!