My first guitar was a 12 string & I gotta concur.. it's a great sound but probably not a choice for your only acoustic.
I made the mistake of not tuning down mine & paid for it with a warped bridge and I found that only having a 12 string really delayed my ability to play leads and fingerpick for a few years.
As far as tuning, they're a bit of a pain but not really that hard once you get used to it.
If you're desperate to play leads you can always remove 6 of the strings and use a lighter guage... although the neck is a bit thick.
Other than that the only other thing I can think of is if it's a cheaper model guitar, it'll be hard as hell to play in tune the higher up the neck you go. Barre chords with open strings are the worst.
The good side of things is a 12 string sounds great for just strumming basic chords or doing Beatles tunes... like the lead from Hard Days Night... or a Supertramp song like Give A Little Bit or Even in the Quietest Moment