Well I finally finished tinkering with my grid-based rules (see link). And have been trying them out with my new Chaos Marines an army I'm slowly adding to. The changes were in the areas of interventions, weapon types, combat, and vehicle damage. I'll carry on playing with this set for a while now before thinking about any more modifications.
A view from the Chaos Marines at the start of a game.
Space Marines advance towards their objectives.
Last week I bought One Hour Wargames by Neil Thomas which I'm now reading and will no doubt tryout some of the scenarios. Looking at the rules in the book I thinking my rules appear somewhat bloated at seven pages.