The only problem I found with the cooling pro radiators is the filler part is only pressed in rather than welded, so after some time it'll break off! But this isn't limited to the just jap radiators, i believe a few others are the same!
If you get one, I'd get that bit welded on to catch it before it happens. But then again, it does have a 12month warranty where they'll replace it if it breaks. Some of my mates are on their 2-3rd radiator!
I also don't think that the cooling of those radiators will necessarily be better than your stock one (provided it's not stuffed)
If it were me, I'd invest more time and money into increasing the air flow through the radiator because I believe that's where you'll see a bigger benefit!