I have a mini convertible crib. It works perfectly in our one bedroom apartment. I liie it because it doesn't take up much space and it was inexpensive.
I got a mini crib as a gift, it hasn't been put to use yet but I love how it just fits in my room to keep my little one close at night until she starts sleeping through the night. That's when I'll put her in her regular crib in her nursery.
My sis had one. They're more than a regular crib. The bedding also costs alot more with not many selections, and I think the mattresses cost more. Plus they cant convert to anything like the regular cribs.. only benefit is they are a few inches smaller i guess.
Some cribs are actually cheaper the the mini ones anyway lol
Everything I've heard about them aren't that great people told me it's not worth it because you'll have to buy a fullsized crib after awhile anyway so you might as well just get a crib.