Since the new fed system is running, and entrances loose their worth due to that I am thinking about it.
Think about it this way. I only think about buying Stamina, HP and maybe some block there - I would spend :
50K FE + 2K EP (Gym 1)
10K FE + 1K EP (Stam 1)
10K FE + 1K EP (HP 1)
Total: 70K FE and 4K EP (80K + 5K including Block)
This alone would give me: +20 STamina, +50 HP. To buy that with advanced techniques, I would have to spend:
STamina (5 + 10 + part of the next level) = 3,5 K EP (rough number since it's not exactly in the middle of the third AT)
HP: (20 + 40) = not totally 3K EP.
This means, as a rough number, to gain the same effect with AT, I would have to spend around 6,5 K EP. If I take in another Gym-Option (like 4 points of block), this goes even further. And you should keep in mind that most of us are not starting with STamina AT, so they would probably have to calculate that in different numbers.
Actually, you're trading some money for EP. The point is, is it useful or not? That depends on how entrances develop. In this small example (Stam+HP+Block), I would trade 80 K FE for roughly 3-3,5 K EP. Sounds like not totally worth the trade, but well, it has the advantage to be achieved much faster (since my related AT'S are higher and for Stamina I need 10 K EP first!) Also I heard the Workout-Stats go to your "Basic-Pool", which means the 20 STamina from the Gym would also be multiplied with your Tireless Attribute (going for 24 instead of 20 Stamina in my case)
I am not sure. Right now, I will start gaining some money and then will think about maybe trying out to buy at least the first levels of the named Gym-Techniques. I don't think it is that wrong to completly deny it. I am not sure how that entrance-thing in federations works out right now, though.