I'm still on the fence about it, but 80% in favor of the design. I personally feel the sides could have been styled much more aggressively... quite happy with the front. The rear is not terrible, but could benefit nicely from a more aggressive diffuser.
I'm hoping the Abarth will address the concerns about the vanilla styling. Keep in mind, the 124 is similar to the 500, in that most of the customers won't give a rat's arse about speed or handling... they want something that simply looks cool and provides a taste of the Italian experience. So, with that in mind, the 124's styling (or lack thereof) is "middle-ground" enough to attract a wide range of buyers. It appears Fiat wants this to be a volume seller, not a mad track rocket.
Here in the USA, the Miata (event the most current one) is a bit of a hairdresser's car. It has a massive following in SCCA racing, and is an extremely competitive chassis. But, it lacks street-credibility due to the lackluster 0-60 times (the only real measure of dominance for us Yanks).
Personally, I'm not bothered with that. I am interested in the 124 (the Abarth especially, if it's within reach) because I like cars that are different, cars with more character than credentials. I have zero desire to buy "what everyone else is buying". If the 124 has the same chassis as the Miata, and has some Italian soul in the styling and powertrain, I think it would be a great combo. The Miata aftermarket options (suspension, wheels, etc) are abundant. The 1.4 is a plucky little motor that can be EASILY woken up to 200 horses. If the 124 weighs ~1,100 Kg, it should be a blast in the mountain roads of Tennessee. If the Abarth model is released with the 4C's 1.7, I think we'll have a proper "pocket rocket" on our hands.
Time will tell.