Not that I'm an expert but as I was recently in the market for an intercooler the double capacity ones are practically the same, if not more money than a full front mount. The full front mount is obviously better but thats not to say the double capacity ones are a complete waste of time, just that there are now better ones available for the same money, making them the obvious choice but if you have a pace double capacity in the garage and wanted to run a bit more boost the £400+ it costs to fit a brand new front mount properly might be overkill?