The cheapest BMW M Series currently for sale is an M3 Convertible. $69,050 to START. That's about the same price as a Ford Mustang GT500 (5.8L Supercharged, 662 horsepower), WITH the SVT performance package that includes track-inspired brakes, tires, and suspension. In other words, nearly the most expensive Mustang you can buy directly from Ford. Cost wise, it's also similar to what Shelby will do to your Ford Mustang GT with the 5.0L engine (including the cost of the car), with a couple of their models.
So comparing a well optioned GT500 convertible to an M3 I get, but again- this is a car with a base price of $21k! You can have a 400+ horsepower V8 and brembo brakes for under $30k! I just don't think it's fair to compare it to the likes of the higher end BMW's, et al. Not at ALL saying the Mustang doesn't have it's shortcomings- but I think it's european styling is going to our heads and we're forgetting what it really is.
Just curious (and you very well may have) have you driven a GT500, or a Boss 302, or a Laguna Seca, or one of the other $55~$70k Mustangs that are more 'track oriented' (and priced more similarly to the BMW M Series?). Just curious if you found them to be just as inferior- I don't know- I've driven neither an M3 NOR a high end Mustang. So I'm just curious. I do enjoy driving a Mustang- but it's definitely inferior performance wise and tech wise to a LOT of cars on the road today. Doesn't mean it's still not fun. The other thing is, a Mustang is still a capable daily driver. Something you can own for 10 years and put 200,000 miles on. A V6 or GT/GT Premium's brakes will last far longer than most other sports cars, as will the tires, engine, transmission, clutch, and other components. Again- an entirely different class of sports car, really. Now you can daily drive an M3, or even a Porsche 911 for that matter. But the cost of ownership is much, much higher than that of a Mustang (though the cost of ownership of a GT500 or similar is much higher than a V6/GT).
My $0.02 anyway. I think there are a lot of great cars out there today. But I think we're getting a little carried away if we're calling it a bad car because it doesn't compete with the M3. My Focus is comfortable and peppy- but should I call it junk because it doesn't compete with the Bentley Continental GT? Okay- that's a bit of an exaggeration. BUT, it would be like comparing my SE Sport Focus (not the ST model or even the Titanium trim level) to an Impreza STi or something else like that. Far different price, market, and performance. Again- there's a lot of cars called "Ford Mustang" and while they all look the same- they are pretty different. The GT500 will hit 200mph on a track, the V6 model will hit 30mpg on the highway!