Do you think the "Premium Tube Series" by Native Instruments can be good? Have you tested it? Would you use it to simulate outboard gear were you not to hve your outboard gear? Elsewhere you stated NI made some of the best effect plugins, which I didn't expect. So now I'm intrigued by these Thanksgiving discounts at NI and seen the Premium Tube suite for the first time. Since I mix in the box, maybe I should give it a try. Is mixing in the box obscene?
I've never used them myself but NI plugins are usually of a very high standard. Is there a demo you can try?
It's not really a case of simulating hardware gear anymore - plugin FX have evolved to a standard now where they stand up on their own. In many ways they are superior to hardware FX ["look-ahead", instant recall of settings, ability to instantiate as many devices as your CPU will allow] so the question is redundant.
Mixing in the box makes most sense to most people these days. Probably 90% of the commercial releases you hear will have been mixed ITB and I hear some amazing records on my radio.
My own process is currently a weird hybrid of ITB/OTB and I'm able to make use of the best aspects of both.