Lots of conflicting advice!

I used an MZ-50 for a couple of years in addition to a P30T. I had no problems with the autofocus, which I found to be both fast and accurate, but this is not a good move up from the P30 series if you have existing Pentax-A and Pentax-M lenses.

My recommendation, along with several earlier replies, would be the MZ-5n. This is really easy to use if your used to cameras with traditional dials - like the P30, and will happily take all of your old lenses in manual focus mode.

I would recomend also getting an M-series wide angle lens, either a 24mm or 28mm. These are almost always available on e-bay at give away prices and will allow you to take excellent pictures in much lower light than will be possible with a zoom.

I've seen a used Sigma 28-200 autofocus (KAF) lens available for sale in a local photograhic shop for £65. Its a stubby, chunky lens which takes a 72mm filter ring. The widest apperture was 3.5 or thereabouts

On the face of it this looks a lot of lens for the price, but I've no experience of zooms with this range. Does anyone have any experience or advice ?

I very much want to upgrade to either an Mz-6 or an Mz-7, but I'm not sure what the differences are.

I'd be very grateful for any guidance and view as to which is the better buy.

I'd like to put in a good word for the humble P30t. I owned one of these for many years and found it very simple to use, reliable, and gave excellent results.

I bought a K1000 for the Mrs and have always been impressed with its robust simplicity, but not its weight.

More recently I used an MZ-50 for several years without really bonding with it, briefly owned an MX-5n, and currently have both MZ-7 and MZ-6 bodies. I love both of these last two, really delighting in the fast and accurate autofocus and the look & feel of these two bodies.