Little over a year ago I did a series of 2-on/4-off short cycles, using a 'cut blend', pre mixed test p/tren a/mast p at 50mg/ml each. I did 1ml injections daily for 14 days, followed by a 2 week PCT, then 2 weeks completely off, then start up again. I liked them, and have since done a 12 week cycle of primo and test e at 700 and 250/week, respectively. I may do them again in the future, especially if using harsher compounds like tren.
At the time I was trying to stay under the radar due to work (found out later it wouldn't have really mattered), so this worked out well for me. Each 'cycle' I would gain 8-10 pounds, then lose about half of that during each off period, so I was ending up 4-5 pounds heavier at the end of the whole setup than before. After running through all of them (3 or 4, I forget exactly how many I did), I ended up about 12-15 pounds heavier than when I started (didn't really gain much if any on the last one, but I also didn't increase my calories by much).
BF was too high to have seen any hardening from the tren and mast, but I did put on some solid mass as well as gain some good strength - singled 370 on bench, way above what I've ever done natural, before or since. The beauty of the short cycles is you typically still see benefits during the initial weeks off, even though you were using short esters. For this reason, I would go more than 2 weeks off before going back on. But 4 is about as long as I would go, since the last week before starting back up, I typically would feel weaker, loss of motivation, etc. Also, a couple months after the last one I did a full 4 week PCT independent of any cycles, in order to attempt a 'start-up'. I was feeling lethargic, little motivation to train, lack of drive in the gym, stuff like that. After the stand-alone PCT, I felt back to my normal self.
Pretty sure it's covered in the write-ups these guys did on the short cycles, but they are only worth your time if you do a series of them - one would just about be worthless IMO. It may be slower gains, but it spreads out the gains over a longer period, so to speak. By doing 3-4 short cycles, I spread out my gains over 5-6 months rather than one big shot in 8-12 weeks. Depends on your goals and your personal situation, it's definitely not perfect for everyone, and many guys don't see the point - like I said, it fit my needs better at the time. And I guarantee you will see some flaming from guys on here, saying they are completely worthless. I look at it like this - take the amount of stuff you would use for 8 weeks at a decent total dose (around a gram per week). Even if you only do 2 on/2 off, you've just extended the effective cycle of that 8 week supply out to 16 weeks. The two weeks off may be less gains than the 2 on, but you will still be feeling something. You will also be mitigating the health effects to some extent.
If you do a series of them, use short acting esters and use a decent amount - like a gram per week or more.