The 3.5 is a good engine, and yes it does put out more power than the 3.8, but there are times I miss having the 3.8 (I used to have a Bonneville with the 3.8)
The 3.8 in the Intrigue is rated for 195hp/230 ft. lbs of torque, (The Bonneville is rated at 205hp/230ft.lbs due to a better intake/exhaust setup)
And of course the 3.5 is rated for 215hp/230 ft. lbs. of torque, not too mention that both of these engines are probably underrated in typical GM fashion.
Below is a dyno chart comparing a 3.8(From a Bonneville or other H-body) with teh 3.5:
The 3.8 is the thin line, the 3.5 is the bold one, you can see that the 3.8 has quite a bit more low-end grunt than the 3.5, but the 3.5 dominates the higher-rpm range...if youve ever driven both, you will know exactly what im talking about.
The 3.5 is better for all-out, balls to the wall driving, but when you just want to drive like a sane person with some solid power, the 3.8 is much more driveable, because you dont have to push so high into the rpms to get the power you want.
Dont forget that gearing plays a large role in performance as well, two gearing options that I know of were available on the Intrigue, the 3.05 ratio and the 3.29, the latter being more performance orientated.
To see which one you have, you should check the RPO code list on your trunk lid and look for:
FR9- Ratio, Transaxle Final Drive, 3.29
F83- Ratio, Transaxle Final Drive, 3.05
I have the less aggressive of the two, but I can deal with that.