I have an 03 SC manual 4x4 and it will be 10 years come spring that I've had her. I find power quite adequate, and as Darren2001 mentioned, the fuel economy isn't really out of the norm of the full framed 4x4 trucks for the time. I've been running a resistor to replace the pesky knock sensor for the last 8-9 years, but SC maintenance is little extra just to replace the oil every several years. Indeed if you get an SC, run premium, otherwise what's the point and adds what, an extra $5 to already an $80 tank? The automatic uses a smaller pulley for 7psi, my manual is 6psi. There's nothing really extra to worry about and that makes the SC trucks unreliable, or even less reliable then their NA counterpart, other then making sure the sensors are healthy do that it doesn't play with your timing and also cut your boost. If you've got a manual, the clutch is much more old cats, which can be clogged and restrict performance, or can be broken and chunks can get ingested into the engine causing physical damage.
With 33's, I find the 4.6 gearing of the SC a little long and tempts me to switch to the 4.9's.
Regardless, I love me truck and is a great workhorse. I'd replace her in a heartbeat with another one.