the difference between using Sonic Max and using a...well......EQUALIZER
They do different things. EQ can be surgical, allowing you to zero in on a problem area or to enhance something you want to bring out, while the SM is an overall effect, analogous to reverb. I have an SM in my living room stereo system (not a high-dollar setup) and the plugin on my computer. It occasionally gets used, in the spirit of "this part isn't working...what would happen if I ran it through the BBE?" It's all about how it sounds, after all, which is why I advised Mr Myriad_Rocker to listen to it.
Opinions are opinions, and often a particular processor is fine in one context, or mix, and not another. I know a lot of people expect there's one "perfect" setting on the recorder or the preamp or the reverb or whatever, but that's either lack of experience or tin ears talking. If you want it to sound good, you have to pursue what you want, and work for it, not expect to push some magic button and have it go straight into heavy radio rotation.
For this reason a lot of us think the ONLY way to evaluate equipment is to listen to it, find out what it does, tweak the knobs, and generally take it, and yourself, and your sound, seriously.