My daily driver is an AWD hot hatch, that is as quick (quicker even) than my Mustang. I spend money on both ..... though I do get more "value" for the money I spend on the hatch and love driving it.
That said, I do love my Mustang just that tiny bit more and will still own the Mustang long after the hatch has gone. The Mustang is just that type of car .... a real muscle car with looks, sound and performance that makes me smile every time I drive it.
If, however, I get a chance to go to a track (and I do that at least once every few months being part of another car club (and forum)), I do look at whether the characteristics of the track suits the hatch or the Mustang better and take whichever will work better. For that very reason the hatch gets to go far more often as tighter circuits really suits the power down abilities of AWD.
And, yes, there are also far better RWD options for track work out there than a Mustang, almost all hails from Germany .... and I have owned a few of them as well. None of them are/were as desirable to me as the Mustang so I understand why we all have the urge to keep pouring money into a Mustang.
Realistically though, the Mustang suffers from very quickly reaching the point of diminishing returns and I have accepted that and just enjoy it for what it is. I'll do a few more mods (headers and bit more on the suspension) and then leave it as that for many years to come and perhaps 1 day add a 65-67 Mustang to keep it company.