Originally posted by gerax Now, backing up with a crop body means having crop lenses which almost doubles up the weight of gear to be brought on shoulders;
I don't get this. Plenty of "crop" lenses, like DA 35mm, DA 50mm, will work just as well on the K-1, though their edge performance will be slightly less good. Even true crop lenses like the DA 10-17mm can still be used in FF mode at
some settings (zoom and focus), or just use them on crop mode. Secondly, all FF lenses can also be used on crop camera body. All of them.
If you have any legacy lenses, the FA or F or A series, they are also all FF.
The line between FF and APSC lens is not so hard. Its a soft line, and you can push it a little bit.
But if you think you should sell some gear, please, go right ahead. Many people sell something to fund another purchase.
The main advantages of the K-30 are that it is much smaller, especially with a pancake lens. And the K-30 might have a faster burst rate, allow AA-adapter. These might not be big issues, but the size and weight can be important in some cases, for example if you are traveling or if you want to take it to a concert or sports event (where they often won't allow big, professional-looking cameras)
You can find a quick technical comparison here:
Pentax K-30 vs. Pentax K-1 vs. Pentax K-3 II - Pentax Camera Comparison - PentaxForums.com