Olives can be fantastic snakes. Yes they can grow big but that takes a bit of time if you start with a hatchie. Most of them are good feeders when young but a small proportion of them can be difficuilt to start but that's been well documented in past forums. I waited nearly three months before my guys would eat (thanks again to Magpie for getting them going). Now they are growing well and have reached about a metre and a half with good appetites.
They are a dream to handle and alway seem to be very active and inquisitive. They are rarely temperamental and I handle them once or twice a week just to keep them used to the handling. They will become big eaters as they grow and you shouldn't lose site of that.
They are strong snakes with tremendouse jaw strength (ask Bigguy). I guess the main thing to consider is - do you really want a snake that can grow to the size of an adult olive python. It's easy to get caught up in the whole snake business. Make sure that you are getting it for the right reasons - whatever that may mean. Personally I think if you have the space and the funds to feed an Olive and you are confident that this is what you want then I can't see a problem with one as first snake. I'd reccomend that you start off with a hatchie but make sure it's feeding on thawed rodents not finches.
G