I'm moderately experienced with Flight sims- I use a Logitech Wingman Extreme Digital 3d joystick, and extensively use IL2 Forgotten Battles (I'm trying to perfect my Stuka dive bombing technique). I extensively used Flight Unlimited 3 which I found far better than Microsofts then current Flightsim competitor. I don't find Microsoft Flight sim 2004 any advance on previous versions.
The 'feel' is a major failure. the view out of the windscreen is a major failure. The scenery is at best 'basic' and uncomparable with IL2. For all the extensive loading of 'world' scenery, they should have concentrated on smaller areas of far higher definition scenery, like Flight Unlimited 3. Put that lot together, you have a fun 'game' for a short time, probably a superb automatics procedure trainer, but not a 'simulator' simulating 'how' a 737 flies. An aeroplanes 'feel' changes with speed. At high speed, it feels heavy and slower responding, at lower speed, you get perkier response. My impression of the 737 simulator is that it is locked at high speed, so when you are at low speed you still have the characteristic 'feel' of travelling at high speed.
The 737 feels every bit as perky as a 747-200 and -400. Easy to over control if you are clumsy. What I see when I play with Flightsim 2004 is not a 737 like I know!