Bad turbo vs. spool up.....

[ONE_QUIK_6]

Okay, a couple years ago my car ran very good-ported heads, intake, big shaft turbo, 50s, PI 3500 L/U, etc. Well after we install the ported heads it started smoking a little-wasn't sure why, but now I am 90% sure it is the turbo going out. there is not much shaft play, but there is oil residue inside the intake tubes and leaking from the center section.
Now for the question, I am starting to get things all lined out again and the turbo seems to spool much slower than it use to. Can a turbo with a bad seal make a huge difference in spool time?

 

[Taffy]

The bearings could also be going out. If you get enough oil in the exhaust housing, it could sap power.

 

[VadersV6]

If the smoking started right after installing the heads, I would doubt that its the turbo. Sounds more like valve guides or seals. Did you get new guides, or knurled? Were they brass or iron? If there were a bunch of machining shavings from the heads from in improper cleaning job when you installed them, then I could see the turbo possibly getting damaged. But, my turbo is in pretty bad shape (alot of axial play, a chipped blade, coating of oil in the IC and up-pipe, wastegate puck bushing really worn out), but it doesnt smoke. Only a little puff on startup.