Different systems suit different players
AEGs are popular because batteries, magazines and parts are widely available. Gas systems can offer a different recoil and loading experience but are more affected by temperature and maintenance. HPA systems provide adjustable consistency but require a bottle, regulator and site-compatible setup.
Your first replica should match the events you can realistically attend, the support available locally and the amount of maintenance you are comfortable performing.
Do not chase numbers alone
Range, consistency, reliability and handling are often more useful than a headline FPS figure. A Gun Tech or experienced operator can help identify whether a problem is hop, air seal, battery, magazine or maintenance related.