Boas are wonderful! I currently have a little Salmon Colombian girl (Salmon is a line of Hypo). She's the sweetest little thing, and, of course, pounds f/t no problem... Not a big surprise for boas.
The biggest pit fall of boas is their size. For one person alone, they can be a handful. The max size of a Colombian boa will be around 6-10 ft on average, with the males being smaller than females. If you can handle the size issue, though, they are wonderful pets. I currently work at a pet store, and we have an about 8-9 ft female Colombian there. She is SUCH a nice snake. Thanks to her, my dad is now pining after a "big" boa and can't wait until my baby girl grows up. Lol!
On the diet issue, one thing I've noticed is that my boss feeds the big girl at the store strictly birds--f/t quail, if I remember right--for the low fat content, and recommends the same to anyone owning a bigger boa who comes into the store. I'm not sure of the merits of a bird-only diet for a big boa, but, looking at the big gal, she's the picture of health, has great muscle tone, and is still growing, so maybe there's something to that for the bigger boas who are just a little "too big" for smaller rats?