Gearheads of War

I actually gifted my 360 in February to a good friend of mine, (I kept Gears though, he already had a copy) but after seeing some vids of the Hidden Fronts maps I'm really interested in coming back. I'd like to ask some of you who've played them if the maps are worth buying, or will I not be missing out if I wait until they go free, (I heard that'll happen in September)?

Also, how is host advantage and bullet lag? When I last played they could become quite the problem. I'm    curious as to whether these are still prevalent issues.

Thanks in advance. :)