Respect the game organizer and the game he/she's setting up fo you. They put in a lot of time and effort to make arrangements and if they didn't step up...you wouldn't have somewhere to play.
Some games have very specific ammo/mag restrictions. They tend to be more scenario/mil-sim type games. Keeping track of your ammo/supplies and being able to operate your weapons properly are all part of the fun. Often, there's a whole lot of running/creeping around...with brief but intense firefights. You really start to pucker up after surviving a couple of firefights...and are down to just your last mag and whatever's left in your rifle...
Other games are more "fun skirmishes". One team starts in one spot...the other starts in another...both teams rush towards each other in straight elimination, "take the hill", attack&defend, etc.... Lots of shooting. Reload freely during/after each skirmish. Most of those don't really care about hicaps or not...but confirm with the game organizer if in doubt.
When you take a look at 8-10 mid caps (which can be loaded short to 33-35 rounds for "real cap"....or jammed full to 90-120 rounds)....you've got 240-300 real cap shots and/or 720-1200 rounds mid cap. On the higher end...that's a lot of rounds on tap....all accessible with 8-10 simple mag changes. Best of both worlds.
A lot of guys eventually gravitate towards the ammo-limited games...others don't....some enjoy both evenly. To each their own...it's all for fun and good times with your buddies in the end.
(big theoretical generalizations coming up...just for emphasis, not for nit-picking!!!)
Essentially all AEG's on the field perform the same the range difference between a rifle and a SAW are pretty slim. Short rifles like the G36C and MP5 might give up a bit with longer range accuracy in comparison....but essentially for airsoft ranges, they're pretty close (we're talking differences in 10's of feet).
A 0.20g bb shooting out at 400fps out of an M4 is just the same (if not more accurate) than a 0.20g bb shooting out 400fps out of a SAW.
What ammo restrictions do is to prevent every rifle on the field from being turned into a SAW. You can surely rip off a solid 30rd burst from your rifle...but you're going to be out of ammo and out of the fight (which pisses off your teammates to no end!) pretty quick. It forces breaks in the firefight while guys reload, cover their teammates, etc....and allows for guys to move to better positions and apply some tactics.
Can't acheive that on the field with hi-cap mags....you've got 300-500rnds on tap! Personally...games stop being fun when there's non-stop streams of BBs being exchanged and everyone is pinned down.