Everyone's very excited about Vessery, but his ability, while kind of cool, is hard to capitalize on efficiently.
It seems so easy, just TL his target with something else. But Vessery is PS6, and you soon realize that any ship you really want to use TL in Empire is probably a higher PS than him - which means they're going to use it before he fires. Darth Vader would love to pair up with Vessery, especially with Proton Rockets coming along, but that TL disappears fast. Soontil Fel + TC, another common Empire TL piece, has the same issue.
The other ships with TL are so expensive that you're definitely ending up with a 3 ship list, pairing it with ST-321 shuttles, Bounty Hunters, Storm/Tempest squadron TIE/Advs, or other Defenders.
Then, finally, the last problem. If you dedicate another ship's action to TLing Vessery's target, you're likely wasting that ship's action unless it's the first round of shooting at a tanky ship like a B-Wing.
It's a lot of trouble for what is effectively using Squad Leader on another ship...