I agree, the problem most people encounter that makes them believe that first cycles are so good is twofold:
1) Genetic potential (the closer you get to it the harder it is to gain more so adding 20lbs. first cycle will have some impact on the 2nd)
2) Limited time off before 2nd cycle - time on/off is a minimum, that does not mean it is optimum to increase cycle effectiveness. Everyone who has taken 6 months to 1 year between cycles can attest that their next cycle is very effective.
Experience "I had been running more frequent cycles ( using time on/off) at around the 800mg point and gains were very moderate. I took 1 year off and my next cycle was begun at a higher bodyweight and leaner physique (genetic potential should work against) - I found I was gaining very well on 200-400mg weekly - much better than the higher dosage." - I've experienced this several times and IMO the longer you wait between cycles the more effective the next will be.