Been flying the 737 a bit and pretty much enjoying the sim now that I've got some of the camera views and haze under better control.   But more and  more I'm noticing that the speed brakes/spoilers are largely ineffective.  Now .... I'm by no means a real life 737 driver, but in biz jet cockpits I've had the good fortune to ride in, the spoilers are quite effective.  I deliberately fired up fsx as a comparison and they are much more effective than in xplane.  My other "issue" is where to set the correct barometric pressure when using real weather?   And....the altimeter autopilot selection knob seems to take forever indexing to a higher or lower setting.  Is the real aircraft this way?.   

You might want to look up the "ZIBO" mod for the 737 on the .org: http://forums.x-plane.org/index.php?/forums/topic/111305-boeing-b738-800-modified/

It uses the default 737 as a base and enhances it by making switches work correctly, etc. There is also an additional freeware soundpack available for it, I believe. I do not know if your 'issues' will be solved by it, but as it's free it sure is worth trying.

And if I remember correctly from flying the PMDG 737, it isn't the easiest plane to slow down, but I have zero real-world knowledge in that regard...