I've found that the little added weight of the thicker bed is actually beneficial as backlash is virtually non-existent except for perhaps when printing first z+ layer but I have not seen this to be the case.  Heating seems more even and even when shutting the resistor off for a short period of time bed reheats are quicker.

While not knocking the magnet method, I figured the clamping would never be as postive as something more mechanical such as springs or screws.  Plus this way I can adjust tension so as to not over pressure the glass nor to light and risk movement.

But, I want to ask, you losing build area there? That's my one concern with the clip methods - and I realize you can make the metal piece larger (as you may have) but then you have more weight for little reason.

Unless someone can point out a potential pitfall,  am planning on redrilling the metal plate with a few 1/4" holes so that I can mount recessed magnets that mate with magnets epoxied onto the glass plate.

Looks like you machine a new bed and it's quite thick. How has this affected heat up time?

Quick release spring-loaded clips that allow for quick and easy glass changes with no chance of clamp collision.  Dead flat too.