Mine was a lifesaver. I've had heavy, go to bed, take massive amounts of painkillers and feel like I'm in labour periods all my life. In fact labour was a breeze compared to some periods I've had.
Fitted in 1999 after DD2, removed in late 2001 to conceive DS (got pregnant first go after 1 period). Refitted at 6 week check and then only changed as needed (maybe twice) as wasn't relying on it for contraception.
Painful being inserted, ask for numbing gel/take some co-codomol beforehand. I had a crampy, period pain belly for a few days.
First time I has it fitted it took about 3/4 months to settle down, random spotting and light periods. Then - blissfully nothing. Not a smidge, no side effects and no PMT.
In fact, I didn't have a period from Oct 2002 until I asked for it to be removed (I thought it had slipped/could feel it) in 2022. The only reason I didn't have another inserted was because I'm of a certain age and wanted to see what my body was doing re menopause. PMT didn't come back but lighter (manageable) periods did.
I spent many years blessing the inventor, I'm sure I'd have been begging for a hysterectomy after DS if it hadn't been an option.