There is not much lag if your turbo is set up right..I have 13psi of boost at 2200 rpm on an upgraded CT-26 all the way to redline.
Some guys run a small turbo for low RPM and a larger turbo for the higher RPM..
I am back to wanting to use a small supercharger to spool a larger turbo for no lag and off idle boost.. Best of both worlds without the turbo slowing the exhaust flow through the head...
Or use them both together. Small supercharger and a big turbo..
Thats just my idea...