Why great for mixing, but not for listening?
Monitor speakers are designed to have a flat frequency response over the full spectrum and good phase alignment at the optimal listening position (works only in a well treated room though). Hifi speakers are usually a bit more biased with pronounced bass and high frequencies. This makes music more "pleasant" and "crisp" to the casual listening preferences of a lot of people. Listening to loud "hifi" music feels less aggressive than with "ideal" speakers, because of the less pronounced mid-range.
Also, near-field monitors project the sound a little differently than hifi speakers.
On the other hand, you will be amazed about the detail of things you can hear on studio monitors that gets swept under the rug otherwise. This has to do with the fact, that the mid-frequency spectrum is what the human ear is trained to focus on most (speech, animal noises,...).
I would go for studio monitors any day. You will be fine.