My first impressions are that the original design is more accurate, but the redesigned ones are less affected by the wind. More testing is necessary, but the weather has been uncooperative.
I have a Daystate saxon, it shoots the jsb 10.34s great. I was wanting to try the monsters too. A member of this forum was nice enough to send me a tin of monsters! I tried them at 25 meters but they didn't group very well.
remember to try different lot #s of pellets. it can make all the difference even with know makes or brands the gun likes. I try and get my hands on as many different lot #s as I can of the pellets my gun likes. so don't give up on them yet
No different than any other Barrel/Pellet combo ..... vary speeds some and they either play well together or they don't.
My old Gen 1 marauder with factory barrel shoots the 1st gen monsters under 1/2" at 50 yards shot @ 800 fps where as the same pellet in the TM-1000 at same speed has trouble staying inside an inch.