I'm investigating reaction mechanism and I want to calculate energies of my reagents, products and TS on a higher level of theory than I use for the geometries and frequencies.
I'm thinking about MP2, but I've read that is has significant basis set dependence and it's advised to investigate convergence to CBS limit. Can I use double-hybrid DFT as a substituent, as far as I understand they aren't so basis set dependent?
Is basis set dependence a thing to consider for regular mechanistic calculations that aren't pretending to be quantitative?