When I bought my K10 three years ago, I bought it as a kit with the DA 12-24/4 and the grip. I take the grip off fairly often - for long enough to charge both batteries. The camera just feels much better with it. I was in a park last summer (Bar - U ranch in Alberta) and in the cafe, there was a lady with a K10. Naturally, we chatted, and she asked how I liked the grip. I told her I was very fond of it, so for a test, we took her lens, put it on my camera, and she tried the combo. She decided that the grip would be more useful to her than the lens she had been considering. It makes that much difference. Her hands were quite a bit smaller than mine, but even in landscape orientation, the grip makes the camera more stable. The vertical controls are just that much extra, and having the spare card with you even when you step out of your vehicle with nothing but the camera is a bonus.
I never, ever put remote F in my pocket, nor do I put my spare card there. They are way too small for my "where the devil did I put it this time" organizational skills. I've been looking for my check book for two days now.