What is the general concensus concerning the following "upgrades" -

Strut tower brace
Strut tower reinforcement plates
Under strut system (m7)
Rear strut brace

 

If you do a search, there are many "general consensus" on strut bracing

IMHO, for the Cooper, none is needed....'pleny stiff already in stock form.

 

If you really want a consensus, do the research yourself. If you want an individual opinion here's mine:
Strut Tower Brace: Nice under bonnet bling. If you don't track or autoX, probably won't notice its there.

Strut Tower reinforcement plates. Effective if you drive on bad roads often.

Under strut system - too new, jury still out on these. I have only seen post from the vendor.

rear strut brace - waste of time for performance though I have heard reports that they reduce some squeaks and rattles.