There is a task to identify rapidly current variants of potyviruses in potato and tomato plants. What would yo recommend - NGS or Sanger method to make it faster? If NGS, what method shell we use for cDNA library?
the question is, on what base do you differentiate them? Do they have special genes/proteins to differentiate on? Then a PCR might be enough. If it is a single SNP or difference in a single genes activate site (for example) a Sanger sequencing might do the trick. If it is a combination of SNPs you are looking for, probably a PanelSequencing especially designed for this task might be the thing you are looking for. Do you have genes either expressed or not, you should probably try RNA-Sequencing.
I think you might use different methods according to your final goal, as André Marquardt was saying. Also I would say that "faster" does not mean better but if you would like to use a faster method NGS is the case. Is more costly, possibly, but has higher quality data in my opinion.