I'm starting my 2nd STS rotation on the 19th of April (after my last recovery week... I'm officially addicted to STS), and this time around, I'm planning on doing the 3 STS workouts 3 days in a row, MTW (Tuesday Legs) with some running or cycling on those days, so I can do a total body endurance workout on Friday (like Jari Love)...
I just started Meso 2 and I definitely need a rest day in between. I am using 40# dumbbells for squats and 45# for deadlifts and I find that my forearms need a break.
I also do STS weights on consecutive days, I'm doing chest, shoulders, biceps disc on day 1, day 2 I do abs/core-several segments to add up to atleast 50 minutes, day 3-back and triceps disc and day 4-I'm doing legs disc.