Well, all the ways are valid, and not necessarily exclude each other, as each has their pros and cons.
I find that the IC2 is good for massive automation, where TE can yield 50% more, but with a lengthy process (22 minutes or so).
Induction smelter is a great one, especially when combined with a rock crusher to provide the sand too.
The beauty of this mod is that it provides you choice on how to do things, it is no longer a "if you want this, then use that", but more of a "you have X ways of doing it, choose what you prefer", and that is so refreshing, and adds so much to replay ability.