I did ten years TA, 2.5 whilst self sponsored training for CPL/IR. Absolutely excellent, geared my training around TA commitments (flew Mon-Fri, did hour building in the US in 1 month, took a 'Leave of Absence' for the writtens and all in all the income (some £300 per month) kept my head just above water.
As for when in an airline.....forget it. Not compatable. Duty Hours limitations, flexible working hours etc etc, add that to going away for a w/e with the TA and having only 6hrs sleep, would you want to be a pax with someone like that up front? No, neither would any Chief Pilot!
Get the most out of it while you can.