Throttle body spacers

so I had a friend ask about installing a throttle body spacer on his Ram pickup. It has the 6.2l hemi. I’ve read mixed reviews about them. So good some bad. Does anyone have any real world experience with them? If so what has it been?

thanks for any input or information.

I've never personally dyno tested one so I can't give you any solid data. They strike me as an unlikely source of improved power though. I guess the upside is that they're quite cheap. Personally I'd want to see some dyno results before I spent my cash.