I too am a big guy (6' 240 lbs) I bought my K-5 without the grip, I realized that I really needed a grip for it, because like others have said here before-"my last two fingers have nothing to hold onto" once I got the grip, the total setup "just fit" perfectly in my hands, I rarely take the grip off unless I want to pack lite and want to hook the camera onto my belt holster (the Capture made by
Peak Design)
With larger lenses on the camera the grip really helps out when it comes to holding the camera still, a lot of my shots are a lot sharper since I got the grip, however I don't know for sure if it is because of the grip.
Another note- I recently realized (after reading a few threads in here) that I can just plug in the USB cord to my computer to upload images off of my camera. When I first used a digital camera (ever) it was one of those AOL digicams (probably around .1 megapixels) I tried pluggin it in to upload my images but learned very quickly that it took forever to get the images on the computer, the camera would heat up pretty bad, and it would drain a good set of batteries each time, so ever since then I shied away from using the USB connection. Nowadays the USB connections have improved in major leaps and bounds. I used to pull the SD card out and just plug it into my computer, and then when I was done I just put it back into my camera. about two weeks ago I decided to try the USB and I am literally impressed!. There really is no difference in transfer time compared to the SD card, but I exclusively use the USB connector now because of a few reasons-
1) easier
2)Less wear and tear on the camera and card
3)My fingers are just way too big to try and fish out those tiny little SD cards, but I will change them out if I have to.
I use Light Room almost exclusively for my workflow, and yes you can really do some awesome things to your photos with just a few tweaks here and a few tweaks there.
No matter what some folks may say in here about the K-5 classic, it is still a performer and has loads of potential, ya I could look for all kinds of excuses to go out and buy the next big thing (K-5IIs) but I am not that type of person who feels he needs to justify that kind of "pipe dream" chase.
I may one day get the IIs but I want to wait until they come out with another model, and thus I can pick one up on the cheap from one of those types of "pipe dream" chasers I just spoke of. I like getting a new model of something that is at the end of it's "run" because that usually means they most likely have all the bugs and issues ironed out of them by then.
Once you figure out your new K-5 I am sure you will really like it and amaze yourself at the images this little camera can put out.