I Ain’t Been Shot Mum vs And Was

[The Gray Ghost]

I Ain’t Been Shot Mum vs And Was Jerusalem Builded Here?
I play AWJBH but I have heard a lot of stuff about IABSM
so should I stay with AWJBH or move to IABSM?
most of my games run between 20 figures a side to 40-50 with a few vehicles.

[the commissar]

Depending on the period I would go for Too Fat Lardies "Through the Mud and the Blood" for interwar or "Troops Weapons and Tactics" for actual World War 2 games.

IABSM is really company level (100 figures + a side) whereas these others are more "platoon" level

[B.E.A.R]

I enjoy And Was Jerusalem Builded Here and for larger games it is not bad in my opinion.

[Mad Padre]

Hello Gray Ghost:

I don't know AWJBH at all so I can't give you a comparison.
It depends what you are looking for. 
If you want a more unstructured, card-driven sequence of play with an emphasis on friction, fog of war and leadership, then the approach taken by Too Fat Lardies is for you.   As The Commissar said, finding the right TFL rules set depends on the scale you are gaming in.   With 20-50 figures per side and a few vehicles, it sounds like their WW2 skirmish rules, Troops Weapons and Tactics (unfortunately acronymed as TW&T) would be best for you.   
Too Fat Lardies has an active Yahoo group with prompt and courteous answers to rules questions, often by the rules authors themselves.

Mike