I disagree. My suspension, now completely modified, is a lot less forgiving than when it was stock. The main reason is the stock understeer is gone and the added camber makes the steering more "twitchy". Not many people are used to driving a neutral handling car hard or are used to how quickly it now "turns in".
The way the car comes setup from the factory will hide more errors IMO.
I have to disagree with you here, but probably not for the reason you think. In general, the more you mod your car, the larger the performance envelope, but conversely, the narrower the margin of error available. The stock (or nearly stock) suspension won't flat-out pitch you off the track like a hyper-tuned setup will when driven ham-fisted, but it WILL start doing all kinds of obnoxious things, like plowing through the turns (massive understeer), rolling over on the door handles, and just generally ill-behaving. ALL of those are recoverable, even for a novice, whereas the classic "Mustang Snap" isn't at all easily caught. The highly modded suspension will be more neutral when driven properly, and will allow higher lateral G force, but once you go past the limit, it's all over, unless you've acquired some decent car control skills.
When I get into a car with a student, I would MUCH rather have a stock vehicle than one that's modded up... If the ass-end starts wagging under braking, I don't have to wonder if it's braking technique or if it's mod induced, like too high a spring rate in the rear, improper compression valving on the dampers, uncorrected bump-steer, torque-arm induced, or anything else. I KNOW that it's because the student slammed on the brake pedal like a panic stop, and transferred too much weight up front.
In the end, if you're able to drive past the limits of the stock suspension, then fine, but if you aren't, why dump money into it if it isn't a problem (yet)?
