Just recently, both here and on reddit, there have been a number of posts from players wanting to play scum and asking for advice. Generally, the responses collate down to "buy a pair of aggressors". I play a lot of scum (and I love the aggressor -fun to fly, hits hard and is durable (with the right upgrades) so I'm not trying to put it down!)
"Buy a pair of aggressors" is only good advice if you have played X-wing for a while (mainly arc dodgers) and have the following upgrade cards -Heavy Laser Cannon, Autothrusters, Veteran Instincts/Push the Limit/Predator/Crackshot, Fire Control System/Advanced Sensors.
If that isn't you, don't buy a pair. The reasons are:
- The aggressor pack only comes with two cards you see on "competitive" IG builds. Mangler Cannon and Inertial Dampeners. So, you are going to need a pile of upgrade cards (from a variety of different ships) in order to get durable, hard hitting ones. That's expensive (and time consuming if you are trying to buy individual cards rather than the ship)
- They are very unforgiving and hard to fly. Large bases, S turns, lack of a 3 turn mean you have to be very careful lest you find yourself stressed, blocked and at R1 of enemy ships. If you don't have experience with achieving range control and manoeuvring on a large base ship, these aren't the ships you are looking for.
Once you have auto thrusters (Starviper), Crackshot (Khiraxz - this also gives you predator) and at least a Fire Control System (but Advanced Sensors is imho better), then go ahead and buy one (this is for competitive use). If you are playing casually with proxied cards or lists from a squad builder- definitely buy one. But use the money for the second one to buy most wanted, or a hounds tooth instead. You'll have more fun and learn faster.
hope this helps!