Well, I'm not expert on PTW! However, I brought few of them with PDI barrels to mud around at my backyard. Just listen from some other C-Hings opinion:- AEG is pumping / compressing normal air to generate the power and the smooth bore inner barrel with tighter dia. will increase FPS and the reduce accuracy (however, accuracy is personal thing; ie. range of shooting, shooting habit), however, tight bore barrel the longer the barrel the degrade of accuracy. I did read some Japanese magazine explain in detail in physics angle to play airsoft guns, they have the same conclusion as #2 mentioned. The C-Hing summary in actual world both PTW barrels and PDI barrels are high performance and difference is only a cap of the paper thickness. PDI is expensive which make you feel better!
Yes, I agree for PLAYING airsoft game, the use of light weight barrel is GOOD, even the advance rifles finding the way to reduce the weight to increase soliders endurance in combat situation. However, due to cost problem, the suitable material is steel barrels, we try pulling the gun close to the body to reduce the torgue effect and do more back exercise to overcome the pain generate by heavy weight rifles. This is life for solider, but for game warriors we have a lot of choices.