I'm looking at jumping into HPA in the near future and after many hours on Google and Youtube I still a few questions. 1. Are HPA guns worth the money? I know "worth the money" is a relative term. Will a HPA system perform better than an AEG after investing the same about of money in both builds? 2. Full engine or cylinder replacement? For a basic field or CQB rifle are the upgrade options offered on an engine really needed over the less expensive drop in cylinder? 3. SMP or Jack? 4. Regulator, Tanks, hoses. Anything labeled for airsoft gets a huge price increases! Are there better and or cheaper places to get these than an airsoft store? 5. Filling a tank? What is the most common way HPA users refill tanks? 6. How long will a tank last me? On average, with a common HPA rifle set up, how long should I expect a singe tank to last? Is it normal to need a second tank for full day of play?