I had to make do with an Android tablet for about 3 months while I was between laptops (waiting for the 2010 MBAs to be released before I bought a new one) and it was manageable, but just not the same. (And the laptop was my only machine, so that meant this tablet now became my only computer, except for the few times I could convince hubby to let me boot my backup to his laptop if I really needed to.)
One of the big differences was not being able to have to programs open at the same time. On my laptop, I'll often have twitter open or a small chat window that I can see while I'm "in" another (not maximized) program. It was difficult to train myself to only be in one app at a time! (That may actually be a good thing, though, for productivity.) This was also before I had a phone that worked well as a secondary device (like a dedicated twitter screen). If you have a good smart phone, then you can mimic having multiple programs open by simply using multiple devices.
The only thing I really could NOT do was manage my photos. (This was of course summer 2010, so think back to Android tablets at that time.) My tablet had an SD card for loading photos, but even navigating file systems was a bit of a pain back then. App selection and abilities was more limited, too, so I could get photos uploaded to Picasa, but only in a catch-all "uploaded" folder. There wasn't an app for folder management at the time, only for photo viewing. So I couldn't organize my photos by trip, nor could I add my annotations etc.
I also couldn't upload files to my online paid storage, since it only had a browser interface at the time. Also, my Android device had a weird limitation where you couldn't upload files via the stock browser. In fact, each available browser had its own set of quirks that resulted in no one single browser being able to both access/sign into the site I needed and upload files. (It also meant that I could only attach files in a specific email app, not while accessing email in a browser.) This is something I really wouldn't have thought of as a possible problem ahead of time.
I would also not have been able to do this without an external keyboard, which just meant that sitting at a desk became the easiest way to use the whole set up. If on the couch, I'd often have the keyboard on my lap and the tablet propped up with pillows somewhere for viewing, or on a nearby table if something suitable were nearby. It just wasn't as convenient as a laptop.
Things have obviously come a long way in 2 years with more apps, better cloud integration etc. But I basically did what you're proposing (with worse technology options). I did it for a very different reason, though - I was holding out for the MBA, waiting for it to be released before I bought a new laptop. So I did this knowing something new and shiny would be right around the corner, and I was just bridging the gap.
I personally wouldn't give up the more functional machine, which you've said you're delighted with, and put myself through a tablet-only existence. Just to then, what? Go back and re-buy it in the fall? I wouldn't switch, but that's just me.