I bought my x back in 2002 where I tested both the manual 3 vs the step 4.4

Good things about the 3 manual
1) it's a stick - you're in the gear you want at all times
2) the 3.0 engine generally works well with a stick for a SUV this heavy (except 1st gear)
3) BMW should always have a stick IMO. the steptronic will never make up the difference

Bad
1) 1st gear is super short so you end up shifting out of it around 5 mph..annoying over time
2) the 3 is light on torque at low speeds (until 3rd gear) unless you want to really rev the engine
3) stop and go traffic is not much fun
4) your resale value will be weak...but so your purchase price should be low


My two cents