LCD Freeze machine for glass only repairs

Hi all.

Been repairing phones since the 3gs, and do all the phone ranges, including Samsung glass only… up until the S6 when they used a stronger OCA sheet, and it’s a pain to separate!

So, I’ve seen these freeze machines, and obviously the videos make this look really easy, keep otnon the surface for a minute, and “simply” push a card between to separate the glass from the LCD.

Does anyone habe any experience of these? As it’s alot of money to buy one, then find out its not as straight forward with a high failure rate?