There is an 'art' to installing spring inserts successfully.
The thread you cut in the parent metal needs to be near perfect because the spring insert will follow the threads you cut. When you screw the insert in you need to stop at just the right point and then gently wind it back again to get the spring bedded into the threads in the parent metal. Finally you need to snap the tang off cleanly without disturbing the spring and without leaving a stump sticking out to catch on the stud or bolt that you screw back in.
I have successfully used 'Recoil' kits to salvage threads in aluminium on my old motorbikes. I have paid a grease monkey to balls up a Helicoil in a brake caliper and then paid someone else to salvage it using a Wurth timesert.
The Wurth timesert is a more robust (and reassuringly expensive) solution. A spring insert is an elegant solution but won't work if the damage extends beyond the root of the existing thread. You can use Loctite to stop a timesert from working loose, you can't with a spring insert.
If you have the time a man of your calibre should have no problem with the spring inserts. (but if time is money and you need a guaranteed result then the Wurth timeserts don't look so expensive)