I tend to like tight rules for some GB's, otherwise it becomes "build what ever you want and stretch the rules". I much more enjoy entries that honor the theme well and are plausible, and strive to do so for most of my entries.
I also think the GB discussion threads tend have folks pushing ideas to the edge, and beyond, the rules more for discussions sake, or discuss real world articles along the lines of the topic, less for anything they actually intend to build... "what if I add a 15HP Yamaha outboard motor on the back of my 1/700 HMS TITANIC build, does that could as more engines???". I think this is more of banter, than actually serious questions, and it likely drives our esteemed moderators nuts!

I also think it gets a bit muddled when we overlap GB's. We have 2 still open for voting, and folks are already posting for the next one. While I admire the enthusiasm, it can feel like we are on the hamster wheel, or maybe just for me.