did you not read my other post
you know, the one where i responded directly to you
Yes, obviously it's best used in games where you DO NOT tech to T3. What's wrong with that? Nothing. For example, you should never tech T3 if I want to call in T34-85s either. It's just suboptimal play.
If you want to build T3, obvoiusly don't bother with the Stug E.
Teching costs ALWAYS factor into a unit's value.