At 8 points, they're the most expensive modification in 2nd edition. They're also tightly restricted, requiring a small base ship with an open Modification slot. That restriction locks it out from a number of ships that would otherwise love it, like the Skurrg, Fang, Defender and A-Wing.
The fact that they allow a boost after a red maneuver means that they will probably be strongest on ships with K-turns, Sloops and Tallon Rolls in the 3-speed range.
TIE Interceptors seem like they would love it, but I can't bring myself to put an 8-point upgrade on a ship with only 3 hull to begin with. The Advanced is really the only Imperial chassis durable enough to justify it, since the one thing Vader really needs is a Boost.
The E-Wing probably has the most potential here, thanks to their ability to combine Afterburners with Chopper and Elusive. This lets them spend charges from Afterburners and Elusive to regain shield charges for an action, then spend shield charges to regain additional charges in Afterburners. Combine that with a generous array of maneuvers in the speed 3-5 range that can benefit from a free Boost action, a variety of fast and slow red maneuvers for restoring Elusive charges, and a tough statline, and you can probably get a decent amount of mileage from this combo on a simple Rogue Squadron Escort for 76 points. For 3 more points, you can add an FCS, and another 11 points buys you an upgrade to Corran Horn.
The X-Wing can also pull off the above combo, but the lack of red hard 1s, plus lower agility and shield values, makes it a little riskier.