HI Luiz,
In terms of better, it's hard to say, as both techniques can treat your 2M m3/day gas (~ 177 mmscf/day).
The question is sometimes what type of treatment you are looking for, or how much would you spent per m3.
If SulfaTreat is used it'll cost you $0.0015 /Mcf (~ 29 Nm3), & ST material...