You can never accurately predict the temperament or needs of a mix. Mutts (meant as a factual term referring to a mixed breed, not as an insult) don't adhere to breed standards, obviously, and the purpose of a high quality breeder is to strive toward the set breed standards. When there's no standard to follow, you don't know what you're going to get.
How much time do you have to dedicate to a dog? Maltese are prone to separation anxiety, so if you have many long classes, work many hours or are frequently out, they're a poor choice. Poodles are very active and clever dogs, so if they don't get plenty of stimulation and attention, they become bored and frustrated.. and a bored dog is a destructive, problematic dog. Both breeds require a good amount of grooming, so I assume a mix would require a fair chunk of time dedicated to daily/weekly grooming, too.
You mention buying one. One should never support the intentional breeding of two dogs who have just been slapped together. There are plenty of mixes in shelters. Unless one is responsibly aiming to create a new breed (in which case they must be an experienced breeder with a clear-cut goal, and they must know how to achieve it), no one has any business just sticking different breeds together. They're in it for the profit; such mixes are all the rage these days. (That's why shelters are full of 'em..)
If you're buying one, anyway, I assume that means you'd be buying a puppy. I don't think any student has the time to care for a puppy. They need CONSTANT supervision. I'm not exaggerating. In order to effectively housetrain a young puppy, they have to be watched ruthlessly! They're bundles of energy who cannot be left alone for very long at all.
And if you don't get a puppy, but get an adult (who would be much more suitable for your situation), then you oughtn't buy it. There's no reason not to adopt, in that case. No reason at all. In fact, there's no reason not to adopt even if you get a puppy. "Breeders" of "Maltipoos" are producing dogs who are absolutely no better quality, since, again, they're not adhering to a strict standard. A "Maltipoo" is a "Maltipoo" is a "Maltipoo."
An apartment is a fine environment for a Maltese or small Poodle, though, don't worry about that. Apartments are suitable for most breeds, as long as they're still sufficiently exercised outdoors.