I agreed that lowering unstrung weight is a key to better handling -- and why many race cars even more their shocks inboard.
The question however I feel is paramount, what is our intended use for our cars? If we are auto crossing, racing on a traditional race track, or are driving at 8/10's+, better handling is hugely important.
However, to be honest with ourselves, how many of us have the courage to drive our cars at better than 7/10's (other than a really intermittent romp on an interstate ramp or similar). I go for drives with many of my sports car friends, and being candid here, for most of them their car's capabilities are so, so far in excess of the both their driving skills and also their courage take a turn at anywhere near their car's capabilities.
As an example, I am track trained/experienced, and my Z06 (which has a heads up display with a "G meter"), will do 1.14G, whereas our Mazda's do around .84G. Do I ever, on even my favorite, totally-isolated, curvy country road exceed .95 G? NO, I do not. (Though I do have the courage to drive at 1.10+G on a race track with huge/safe run off areas.)
So which is more important to you, IMO the better looks of an 18"+, and paying (if you choose wisely) just a few pounds weight penalty, or additional, more than our Mazda's .84G handling capability, that most never use nor need?