I've always thought the Mustang was a very cool, edgy guitar. I have a thing for vintage Fenders, and would LOVE to get a 1965 (pre-CBS) all-original Mustang in Dakota Red. Don't really care about the condition - some nice wear, dings, and scratches are cool with me.
I have two 1965 Mustangs, both in Dakota Red; one has a 24" scale and the other has a 22.5" scale. The guitars are very easy to play for me; I have small hands and the spacing of the frets on a full-size Fender sometimes makes it hard for me to play certain chords. On the Mustangs I can easily make chords that were out of reach on my 25.5" Stratocaster.
The downside is the guitars sound a bit thin when you play clean, as they are small and have single coil pickups. But when you play through distortion this is not a problem.
What is a problem, however, is the placement of the pickup switches just above the areas of the pickguard where a guitarist will be moving his or her hand back and forth while picking and strumming. This can result in a sudden accidental silencing of the guitar, if you have one pickup turned off and then accidentally knock the other one into the off position.