I've been using the I-Shot Mini Range bag for IPSC matches and its been great. Very top quality product. I like the smaller bag because I holds two pistols, ten magazines, 200rds ammo, ears & eyes and a few other neccessary items without being overly large to carry around. For outdoor IPSC matches, especially large ones with six or seven stages, having everything contained in a small easy to carry bag is great. Everything else, I keep in a Home Depot tool bag in my car. I like to travel light. I figure if I need something not in my range bag, my car is usually not far away. Since I go shooting during lunch 3 or 4 times a week, the smaller bag works great because I can just grab it and go. It is also small enough to shove under the passenger seat (SUV, no trunk) to keep out of sight.
I've seen some people that carry everything they own in their range bag. They have to lean sideways just keep from tipping over from the weight of the bag.
Everybody is different. Some people like to have everything they could possibly ever need, while others (like me) like to have only the bare neccessities. For some, two smaller bags are better than one large one.
Take everything you might want to carry in a range bag and lay it out somewhere. Decide on what you really want to carry around and push the rest aside. Pick a bag you like that will hold it all( within reason
) and go with the next size up.
I know people who bought these large wonder bags to hold all their gear only to later get a smaller one because they got tired of lugging everything around.