As for SF training, I don't expect anything less than what you are experiencing Darykjosef, it's the only training I haven't tried yet and am bored of the big/small style of training. Plus I like the pain.. hell, I was a defense trainer when I left HT. Maybe that's why I ended up leaving. MF/Forward training was so much easier to win with.
I suppose it may not be quite as painful if you're training big men who already have a decent complement of perimeter skills. Timmons did not, for instance (started with inept OD, awful PA and JR), so the improvements haven't been very satisfying. It's hard to get excited when your main trainee pops to mediocre in something.
And funny you should mention HT, because I
am a defense trainer over there.