The reason I'm trying he Pegas clamps is, that I'm one of the guys who constantly over tightens the bottom clamp. The bottom clamp that comes with the EX is a cast aluminum (someone said what the alloy was, but I forgot). After a while (about a year) of over tightening, the bottom clamp will spread and won't hold the blade correctly.
The Pegas clamps are made of stronger alloy that should prevent the spreading, I've only been using them for around 3 months, so I won't know how well they hold up for a few more months. The other brag about the Pegas clamps is that they are lighter and will reduce vibration. My EX didn't have that much vibration in the first place, so I can't say if that's a fact or not. Hotshot actually found a vibration meter or app for his cell phone. He did a lot more stringent testing that the rest of us did. I think he posted a lot of results on this forum, but, ig he's monitoring, I'll let him speak to that.
They are a simpler clamp. For example - that plastic adjustment screw on the EX top clamp, doesn't exist on the Pegas clamp. They are easy to swap out and easy to use as the EX clamps. You can top or bottom feed with them.
Having said all of that - I'm keeping my set of EX clamps and I still have two or three additional OEM bottom clamps. If the Pegas don't handle my heavy handedness, I can switch back to OEM clamps with little problem.
I understand that they really shine on the new Jet saw. Handibunny put them on her Jet and someone else bragged about them on the Jet, also. But they would have to speak to how well they work.
Are they worth the $80 - $90 to upgrade? I would recommend that you get used to the EX before you spend any money on them. I think you'll find the Ex is a good saw to use with minimal vibration and the adjustable aggression is great. If you don't have any problems with the OEM clamps on the EX then save the money for a night out with the significant other.