the reason no turbo lag for glt but for turbo/t-5/r is because the engine doesn't have to feed as much exhaust air into turbine to spin the turbo, u can generate low pressures fairly quickly. hence, turbo lag, is largely from having to wait for the turbo to spool up to jam the engine with even more air.

the normal driving/everyday use other's have stated is because if u look at the torque curve (hp sells publicity, torque =) is for ur butt), the low pressure turbo actually raises faster than a high pressure turbo. it also platueas very quickly at 1800 rpm, rather than past 2500 rpm. having a broader torque curve gives u a more "elastic" engine, u don't have to shift much, think honda's vtec. read my previous post on lpt/hpt differences, http://www.brickboard.com/AWD/index.htm?id=420065

...this doesn't really answer ur question huh? :) sorry, best thing to do is call ipd and ask for their opinion whether the glt with ipd ecu (or another company) is on par with a normal turbo, if not better. more power never hurt anyone right? :) just remember the 2.4L engine isn't as equipped to handle extra heat as the 2.3L is, although i have to say the engine is the only thing on this platform that really deserves volvo's reputation as reliable and stout; well, one of the safest cars applies too.