Re: Baron's '05 STi journal!! read: sloooow progress **winter hibernation**
Cooler EGT's and better boost control (to include quicker spool) are plenty to warrant an EWG.
Generally, people want an EWG for those reasons, the sound, and because they plan to go further. The ability to swap springs to suit your needs is also nice. Run a stiff spring combo and use an MBC to control the last bit of boost to aid in very quick spool and help your top end at the same time. Also you wwon't have to worry about boost creep, which VF39's are subject to.
My free comment is more directed at the fact that I don't see spending the money on an UEL when doesn't get rid of the inferior design.