Just an update.
Used the Cheddies today.
I was using my U2's and balls of dust were fairly common, though that is to be expected on closer targets.
Longer targets were smashed to fcuk!
Very pleasing to see how hard the breaks were.
When I was off, single pellet strikes were hard enough to take good sized chips off...which is always nice!
They have medium brass on them, but had no extraction issues (i have had issues on similar looking cases from other brands).
A usefully fast cartridge, but not overly so. I have a recoil reducer, so I can't comment on punchyness, but a colleague stated that they felt firm, but only in a confident way and by no means harsh.
Nice clean tubes afterwards, no sign of propellant etc.
These aren't just "good for the money", they are good, period.