For my experience I quite enjoy the feel of a totally full nappy though I do not mess very often it can be nice. The smell doesn't bother me too much and can be hidden up to a point with good cover and plastic pants. (I'll probably get disagreed with for this next bit and hope no IC members take offense, but) I would recommend trying it to anyone who has never done it, I can understand why many really don't like it but it is a totally different feeling.
The cleanup for a messy diaper can vary depending on how hard or soft it is, whether you wet at the same time or after, if you sit around in it for a bit (not really a good idea but should be ok for short periods) and squidge it about etc.
when I have done it I tend to use the front of the diaper when changing to wipe down towards the back then fold one wing over, wipe and repeat with the other wing then roll it up from the front. this gives a nice thick protection for my hand and removes the worst of the mess and lets you seal everything inside. Then depending on how it is I either take a shower or use wet wipes to clean the rest. The cleanup is not really that bad and the more you do it the more you get used to it, though some really don't like it and it can be quite smelly and messy sometimes but if you like the way it feels you have to accept it.
I can offer 2 pieces of advise if you really want to try. First do it in stages with a little control. start with just letting a little bit out, don't just squat down and push out a full load. this lets you see how it feels and means there will not be much to clean. If you're ok with that the next time go a little more, if you're still ok with the clean up then next time just let it all go.
The second bit of advise is that there are ways to simulate a dirty diaper without actually doing it, you get a similar feel without the smell and with slightly easier cleanup. Careful here as some of the methods people use could be harmful though there are many safe ones.
hope this helps.