You should drive one before making that decision. The 2004 model 4.3 (still available in the S10 Crew cab and in some of the full size half tons) is rated 190 HP at 4400 RPM and 250 ft.lb. torque at 2800 RPM. The new 3.5L I5 is rated at 220 HP at 5600 RPM and 225 ft.lbs of torque at 2800 RPM. So, it actually will make 30 more HP and 25 lb-ft less torque. It feels good when you drive it. I think it's also good that they finally came back out with a complete range of styles, including regular cab, extended cab and crew cab models...all available in 2 and 4 wheel drive. The fuel economy is better also. I owned a 2000 model S10 ZR2 and loved it but the fuel economy left a bit to be desired. I went to a full sized Z71 with a 5.3 and got as good and often BETTER fuel economy than the ZR2 did.
Don