Individual experiences may vary, especially with rimfire ammo and .22 autos. If I want to shoot pretty groups on paper with a .22 rifle then I'll buy the CCI high velocity.I guess the truth is out there somewhere, but when it comes to Thunderbolts, I'm not investing the time, money, or effort to find out.
I was more interested in cheap ammo for my Walther P22 than anything. Right in the Walther manual it says to use high velocity ammo only, but the only reason I have a .22 pistol is to get plenty of practice without breaking the bank. I tried numerous bulk ammo packs and nothing would reliably cycle through the P22 except the Remingtons. The Remmy rounds cycle upwards of 95%. The next closest is actually Wolf which is probably right around the 95% mark as well. While 95% reliability would never fly for a carry weapon or SHTF rifle, that's plenty good enough for me when I'm wanting to put 500 rounds through my P22. It actually gives some added training value by having seldom occuring malfunctions, it's good for practicing IA drills.