When's the last time you've spent three hours on a paintball field? Three hours without taking off your face mask? Three hours in the game? If you play typical recreational paintball, where games are size and time limited, chances are, you haven't spent that long on field. However, for scenario players, the situation isn't that unusual. A lot of what appears on this website originates from people who spend hours at a time in the game, and there can be some major differences born of that perspective.
Anyone can take the paintball equipment they are using right now, jump into a 24 hour scenario game and have a blast. A player can easily extract himself from the field at whatever point to reload, resupply, and replenish. That's fine for the people who want to play in that manner, and many in fact do. But to me, one of the unique aspects of scenario games is the use of re-incarnations and on-field medics which allows continuous playing time. The fact that we (most of The Pukin' Dogs, anyway) enjoy that kind of thing is one of the reasons our opinions may differ from other players on various issues.
As an example, one of the areas our players seem to diverge with the paintball mainstream is the choice of Co2 over HPA (High Pressure Air, Compressed Air, etc.). There's no doubt that for most rec ball or tournament applications, HPA offers enough distinct advantages to be a superior gas source. However, to us, the advantages offered by Co2 as related to long scenario games outweighs anything HPA can offer. Co2 offers more gas from a given physical size tank, which translates into more time on the field.  A relatively cheap and small 20 ounce Co2 tank can provide more shots than all but the biggest and most expensive HPA tank. For the price of that one HPA tank, I can buy a several 20 ounce Co2 tanks and easily have enough money left over address the temperature induced pressure fluctuations which are the most critisized aspect of Co2 (addressed elsewhere on this website) -- not to mention the fact that I can fill those tanks before I go to the game, and not have to spend time off field waiting in line for a refill during the game. While HPA may be the better choice for most players, from a purely practical standpoint, Co2 works better for those of  us who want to spend a lot of time on field.
When it comes down to it, the time on field is probably the biggest issue governing the things we do or use. Most of the players on the team have some kind of hydration system, such as a Camelback. They don't always get used, but when the heat is up, the Camelbacks come out. To someone who plays half hour games, the price of such an item may seem like a ridiculous investment (and for them it is), but to those of us who spend several hours on field on hot days, that bag of water can literally be a lifesaver.  Dehydration can hit before you realize it, and on a large field laid out for scenario play, the nearest water may be a long walk away.
Many scenario players use slings to carry their guns - something which is largely unheard of on rec ball fields, and sometimes riduculed by people who don't understand.  But anything can and will become heavy after carrying it around for several hours. On a long walk off the field, a sling can be your best friend. A similar concept applies to items you wear. The comfort of your face mask, paintball haulers, your shoes and other apparel can be two entirely different things when comparing 20 minutes to 2 hours.  Even the way you play and how fast you shoot paint can become a consideration when you're in the game for multiple hours.
Playing scenario ball does not require anyone to be on the field for three hours at a time, but instead offers the opportunity. It does not require the use of any particular type of equipment, but instead offers the opportunity to make practical use of different ideas. For scenario players, taking advantage of these opportunities is usually a continuing learning process. After a while, you begin to learn from experience what works and what doesn't, and it's not always the same formula which works in other forms of paintball. For example, you can argue the technical superiority of HPA over Co2 from now until the sun explodes, but that doesn't change which one works better for us. We've tried it both ways and the answer is obvious. Does that mean our ideas and opinions are right for every paintball player? Of course not. But do they work for us? Definetley. It's all about perspective.