General or Twilight Anesthesia
For the procedure you are planning, I would be very leery of the surgeon who only uses twilight anesthesia. This frequently means that he/she probably works in a non-accredited facility and cannot get a certified anesthesia provider to do general anesthesia. If that is the case, you will not have one available for the twilight either. When done properly in an accredited facility by a certified anesthesiologist, both methods are exceedingly safe. However, since general anesthesia uses mostly gases that are quickly expelled once turned off and the medicines used for twilight anesthesia take 24-72 hours to be metabolized by the body, the recovery from general anesthesia is much quicker when done properly. This and the fact that general anesthesia has less nausea postoperatively are the main reasons I switched to general for almost everything major over 20 years ago.
General anesthesia safe for revision breast surgery
Both general anesthesia and intravenous sedation (twilight) anesthesia are safe when provided by a qualified Certified Registered Nurse Anesthetist (CRNA) or anesthesiologist in an accredited surgical facility. For the type pf revision you are considering I would go with general anesthesia. IV sedation requires a lot of local anesthetic to be placed and you risk pushing the limits of how much can be done that way.
Anesthesia and surgery
Both are good options and used for different reasons in different patients. Both usually do equally as well in terms of recovery.
Which is safer, easier to recover from--twilight or general anesthesia?
Any revision unless very minor should be under general anesthesia in my opinion. Sounds like you need a rather intensive revision.
Twilight or general
Having done the first thousand or so breast augmentation's using a twilight anesthetic and comparing that experience to the last 2000 using a laryngeal mask general anesthetic, there is no question in my mind that the patients having today's general anesthesia recover more quickly. The amount and type of medications needed to keep one pain-free with just local anesthesia, in my experience amount to more than what is necessary to give when you add a gas. Just one plastic surgeons experience I'm sure others will disagree. Good luck.