First hand experience with both. Eldest son (RHP) had traditional TJ. Middle son (javelin thrower) had TJ Lite + labrum repair.
As stated above, recovery for TJ Lite is much faster because it's a repair of the existing ligament rather than a replacement. Therefore no ligmentization of another type of tissue is needed. The ligmentization process is what takes so long for TJ recovery, and uncontrollable variables in that process are one of the factors in TJ recurrence.
The internal brace was described by #2's doctor as a "kevlar bandaid." It essentially becomes part of the ligament as it heals, providing permanent reinforcement. Doctor said that in theory it is practically impossible to re-tear the UCL after this procedure, though there is no long-term data available since the procedure is relatively new.
Contrary to 24fan, it can be done on a fully-torn UCL. (My #2 son's was a complete tear.) The primary limiting factor is actually the nature of the tear. A long-term, progressive tear ("chronic tear") will typically have a lot of fraying, ragged edges, scar tissue, and calcification, which makes it unrepairable and therefore traditional TJ is required. A "clean" tear due to a single overload ("acute tear") is generally necessary for TJ Lite.
Unfortunately, MRI images may not be able to show whether the condition of the torn UCL is suitable for TJ Lite. We went into #2's surgery expecting TJ but hoping for TJ Lite.