While I waited for 5150: New Beginnings (which is now printed and bound and I just need some time to read,) I started looking for other Two Hour Wargames (THW) products. The pulp-era games are interesting but I still have to prepare a minimum set of minis and terrain for that period before I decide to get those rules. So I found Modern Havok, a rules set written by Ed Teixeira for Rebel Minis.
Modern Havok is quite similar to Chain Reaction 3.0 but with differences (some of them subtle) that make the game simpler and possibly faster and more lethal. For instance, Stars aren't so tough and there aren't as many states a figure may be in (like Hunker Down etc.) Melee combat is also different, and most of the time faster.
For me, the three scenarios at the end of the book (Liquor Store Holdup, Man Hunt and Raid) make it worth. Lots of good ideas, like the Draw Down system for resolving an armed "face off" between opposing groups, reaction to police arrest attempts and a way to simulate a larger battlefield in a 3'x3' table.
I ran a quick test scenario with these rules. It was also a chance to try some hand-draw buildings I've been fiddling with (in preparation for some improved versions.)
During the game, the rightmost marker (on the above picture) turned into a group of three rep 4 gangers. The leader was armed with a semi-automatic rifle and the two others carried pistols. I used the Draw Down mechanic (from the Liquor Store Holdup scenario) to have both groups see each other and react drawing their guns. The enemy gang fired first but missed. The two thugs with shotguns on my group ducked back behind the two-story building and my star stunned the enemy leader. Using the "flock of seagulls" mechanic, one of the civilian groups retired from the table while the other two ducked back behind buildings.
On the following turn, my group advanced and the enemy didn't roll well on their In Sight reaction to my thugs leaving the cover of the building. This allowed them to fire again, taking all three enemies out of the fight. The civilians remained ducked back as the firefight continued and my gang members, having dealt with their target, ran away before other threats would arrive.