I've got all of Klanghelm's plugins. I use all 3 on every project. I also highly recommend Hornet's plugins.

I have real VU meters as well as VST versions. The real VU's are hard to beat and are the best. I have however devised some tests to test the ballistics of VST meters in comparison to the real ones. The Klanghelm meters are the closest for me. BTW many others are not in the ball park so be careful. They will all read 0 dB VU with a sinewave tone but that is not the issue. It is how they move that is way more important. Many DO NOT move the way a real VU does.
 
I have not had issues with the Klanghelm meters either in terms of graphics so that must be something that is an issue with your system.
 
Be careful altering the settings for the rise time and fall time. You can make the meter overshoot if you are not careful which in turn will make you alter the gain accordingly. eg If a meter overshoots you will be inclined to lower the gain. If the meter is too slow in responding it will not reach 0 dB VU like it should so you can end up pushing the gain instead. (reducing your headroom)
 
Where many fall down is when the signal drops to zero and the meter needle goes back to -20. The real VU's have this lovely tiny bounce, most of the VST's dont do that. Seems like that might be hard to emulate, because the bounce sort of adds to the ballisitics of the meter obviously.
 
But don't worry, in terms of music they are very good. I find I have to tweak the rise time on the Klanghelm meters to be around 200 mS or even 150 mS to get the rise time to match the real ones. I know this is not in line with the 300 mS standard but with music that is the only way I can get the VST's to be very close to the real deal.
 
Fall times can be 300mS or under even 250 ms or 200 mS. For some reason the real VU's fall quite fast and will usually beat a VST to the -20 position on the meter.  Speeding up the fall time improves this but it is still not perfect though. On music (as opposed to the pulsed test tones I created) they are very close and certainly are reading right in the ball park.
 
I have got the overshoot control set to 1 or 2. Dont turn this up because that really screws up the meter operation.

Jeff Evans
... BTW many others are not in the ball park so be careful ...

 
FWIW ... in my tinkering, HoRNet, although bar vs needle, shows the same readings as Klanghelm.
 
@Metz - re framerate ... mine's fine ... a bit of an unlikely but possible thought(?) ... is your monitor(physical) / display(virtual) all synced at 60Hz? (or the same).

 
@Metz - re framerate ... mine's fine ... a bit of an unlikely but possible thought(?) ... is your monitor(physical) / display(virtual) all synced at 60Hz? (or the same).



Monitor settings are fine and set to 60hz. But the problem could definitively be on my end anyway. My Melda plugs have a very good update speed but they use the GPU for the grapichs so they work differently I guess.
 
I have to add here that its not really a problem, the meters are still the best VST meters Ive used.