Quick and basic comparing test:
 

Nomad Tren 100 on the left and CDG Tren 100 on the right.
Both are rated as 100mgs/ml/10ml

Nomad vail measures 18.86mm in diameter and a volume calculation will put 10m of fluid exactly in the line A. The actual calculation, taking the bend in the vail base and the meniscus into account yields 10.56ml

The CDG vail measures 20.5mm in diameter and the same volume formula shows 10ml occurring at line B. The actual
level is at C, yielding 8.48ml, a discrepancy of over 15%.

 
 

One can also clearly see the solution breaking down in the CDG vail, not to serious but both vials where left standing for 7 days to see if there would be any breakdown.

Conclusion:
A 1% discrepancy is acceptable in both directions on injectable,
15 % is certainly high and may be an indication that weight rather than volume was used but that's just speculation.

Many people have used CDG products without any problems other than the volume discrepancies. Personally I like getting 10ml if I pay for 10ml but some of the compounds on offer from CDG falls into the "hard to come by" category and one may take the view of foregoing the lower volumes.