I upgraded from k-x to k-5 a couple of weeks ago...last night i started to compare images from both cameras and i must say upgrading was a GREAT decision.
I dont shoot birds (literally) myself but ive taken a few action shots and managed sharp images which i never would have got wih my kx.
Also, comparing same lens on both bodys, definately felt the kx sensor suffered much more from chromatic aberration.

I know what your going through because on paper i couldnt see enough difference to fork out another bundle of cash, but after taking the plunge have no regrets at all!

I am jealous!
Obviously 645 would be a dream, but a friend of mine has the Cannon 5DMk2 and it is an awesome camera!

Great camera choice...
i bought a few books to learn the basics, really helped me.

Can i ask if you are going to buy another Camera? if so, which one?

I have copied below the two links flickr takes you to for forgotten passwords.

YAHOO ACCOUNTS -
https://edit.yahoo.com/forgotroot?done=http%3A%2F%2Fwww.yahoo.com&src=&partner=r...

GOOGLE ACCOUNTS
https://www.google.com/accounts/recovery

Hope this helps you get back in!

I remember seeing that the day it was on the BBC website...i was really proud to see a Pentax camera entry.

Well done!

I'm sure the Pentax is best, but i bought the Tameron due to budget restraints...i have no regrets, i think its a great lens!

Example images below...if anyone has examples of the Pentax i'd love to see them.

http://www.flickr.com/photos/mhorrocks/6319444345/
http://www.flickr.com/photos/mhorrocks/6296005791/
http://www.flickr.com/photos/mhorrocks/6296008347/

I thought i'd pass on a few things a learned tonight when trying to tether using the Pentax K-5.

Firstly i had no luck with hardwire linking to lightroom v3.0. i know i could link with a eye fi card etc.

I tried linking to PK_Tether which has been succesful with the k-x, but with the K-5 was hitting some common problems.

My first shots had green lines across the screen, this seems linked to ISO as when i dropped below 1600 they disappeared.
Next problem was when i shot in burst mode, the camera/cpu link crashed which left my camera LCD on even after i switched it off...when the panic subsided i realised i had to take the battery out to reset.
This happened a lot until i switched to single shot mode, after this everything seemed to be ok!
next problem was the flashing LCD on the top of the camera, the guy who wrote the software said this can be stopped by turning off the LCD luminating in the settings...this didn't work for me as when i plugged in the USB the camera reset this?

The last thing i would say is, make sure that you switch the camera off before tkaing out the USB or you may freeze up the camera, back to battery out...

All in all i have read many positive things about the software, although i personally am going to keep my k-5 away unless the bugs are sorted!

Check this link out. This guy uses a K5 and transfers via eye Fi straight to an Ipad2...

link

Ipads are great but do not have inbuilt usb ports. Although you can buy a connector to overcome this.

I personally would go with an Android tablet for true tethering...

Hope this helps.

Firstly great choice with Pentax!
This isn't so straight forward, i originially had a kx before upgrading to a K5, but have also used the kr.
The kx is an awesome camera, even though the kr has a higher ISO setting, the kx has less noise at an equivalent ISO.

However, i will make your choice easy (maybe)...the kx does not show which point is in focus, whereas the kr flashes a red point within the viewfinder on the point in focus, this really helps!

Kit lenses are great too, depending on the current bundles available, it generally only costs a couple of quid more to get the kit lenses included, and as said before these can be sold on ebay to cover some of the costs when you are ready to upgrade.

I take a lot of architectural snaps, wide angle is ideal, but i would suggest a telephoto if you want to snap detail too.

Let us know whay camera you choose!

M.