The only problem now is that they're getting so old. It's hard to find one in good shape...and you'll have to do a lot of maintenance type work to make them really good, reliable cars. Replacing all the worn out, 20 year old parts, paint jobs, etc. - which can be annoying sometimes when you have to spend money on that instead of the "go fast" parts.
But I'll keep my fox for as long as I can. This is the third one I've owned over the past 11 years (since I was 17). I sold my 85 when I first moved to Germany in the Army and missed it a lot more than I thought I would. Bought a 93 that lasted me for 7 years before I wrecked it. Told myself my next car would be something newer........but ended up going right back to the fox. I guess I just have to have one.
To me, they just feel right. Other than the foxes, the only Mustangs I'd want is a classic (72 or earlier), a 94/95 Cobra, a Termi, a Bullet or a Mach 1....or of course a new Shelby GT500, but that's not very realistic for me. If I bought a new car, it would be a daily driver - not a replacement for my Fox.