I've kept both and personally I like Burms better. If you want a big snake, boas hardly qualify, but burms can get quite large. The burms I've know just seem to have nicer personalities then the boas I've known. I guess it all comes down to, 'what do YOU like best?' In any case I would suggest getting a small one as your first. That way you can grow into them and make your mistakes while they're still small enough that those mistakes won't have as serious of consequences.