It's all relative I guess - I never had any type of SLR camera before my K10D, only p&s so my first thought on focus was 'WOW'. I'm sure I would have the same thought now if I used a Canon / Nikon / etc.
RiceHight - I don't understand why an MZ body would focus faster than a new body - I'm not doubting you and have no experience of this, but I would have thought that at worst, it would be the same?
I have 2 issues with all the complaints regarding AF speed:
1. I am guessing here, but I bet all the people that like to come on here to complain don't follow this up with a complaint to Pentax themselves. I'm sure if Pentax were receiving hundreds or thousands of complaints and requests all for the same thing they would look at this.
2. If you're your camera doesn't do what you want / need it to, go and buy something else - you may lose money and not be able to buy as much stuff you had previously, but 1 camera with 1 lens that does what you want is better than a lot of gear you will never really be happy with and you will build up your system again.
These points are really not hard and 1 may resolve your issue in the future and 2 will resolve your issue now.
If you go with no 2 can I have first dibs on any bargains?