Should I Replace Crystal Mounts Immediately?

I inherited a small collection from a relative - generally unused commemorative stamps from the 1940s to the 1960s that are mounted with Crystal Mounts. The collection also included a few packages of Crystal Mounts of various sizes.
Based on a couple of comments I have seen, my sense is that Crystal Mounts are considered inferior to other types of mounts (e.g., Showgard, and perhaps others). Sorry to have to ask, but why is this? And should stamps mounted with Crystal Mounts be remounted with other brands immediately?
Thanks in advance for your responses!

Inferior would be an understatement. Crystal mounts were more likely to damage stamps than protect them.

Thanks, JLLebert. Do you know how the stamps would be damaged? Damage the gum, change the color, or something else?
In any event I'll start replacing these mounts right away (and toss the bags of unused Crystal Mounts). I'm just trying to figure out if I need to do anything to these stamps during the remounting process.
Thanks!

They shrunk/squeezed the stamps

Not only did the Crystal mount plastic sometimes shrink, damaging stamps, but they could leak adhesive which threatend the stamps and nearly always badly damaged the album pages they were mounted on. On the other hand, in remounting a few pages of stamps that were in Crystal Mounts in my own collection recently, I found I was lucky that most of my Crystal Mounts had not succumbed to these problems, so it is possible that they won't damage stamps. It may have to do with how the albums are stored. Heat may activate the breakdown of the mounts.

I removed all those mounts and replaced them with modern black-backed mounts. Crystal Mounts are all clear so you can see the brown adhesive staining through them.

You often cannot just pull them off the page, but using a razor knife you can cut them open, remove the stamp and then slice the rest of the mount off the page, leaving a small part of the back of the old mount still attached to the page. Over that, I placed a new mount. Of course, with the Crystal Mount adhesive still there, who knows what might still happen, but these mounts were well over 50 years old, so I don't imagine their remnants will disintegrate. You'd be wise to remove all Crystal Mounts you come across. It takes little effort to do this.