Im 25, here's how i run it.
GH cycle for 9-12 months, overlaps with AAS cycles and IGF-1.
IGF-1 50-60 mcg ED pwo 4 weeks on, 4 weeks off. GH 2 iu ED, either in the AM or 4-5 pm.
I haven't use insulin in a while, and I dont think I will anymore. Even with a super strict diet it's easy to add fat with slin. It's dangerous if not used carefully, and basically all it did was made me tired. This was back a few years ago, before I realized that genetically I was gifted in being able to add mass easily, and don't need insulin.
I've never been a proponent of the hi dosing of IGF. And most of the reviews I've read from people that have tried both state that they didnt notice any difference between 50 mcg and 100 mcg. But if you are sure that more is better for you, by all means have at it.
As far as what the combo offers that I've noticed, first of all, size, obviously. Second, amazing (and sometimes unfortunately painful) pumps from IGF. Third, increased hunger from the IGF but at the same time losing fat. Finally, being on GH for a long period of time WILL keep you leaner than you would have been without it. That does not mean that you can eat like a slob and get ripped. You can easily get fat when using GH, but all I'm saying is that you will be leaner with it than without it, all else being equal.
Also, you may find it advantageous (i surely do) to tweak your diet a bit on IGF. You will have increased hunger, and personally I always crave carbs. When using IGF I consume anywhere from 500-800 g of carbs a day. 100-150 are immediately post-workout, and another 150-200 are an hour after that. The point being IGF-1 will shove those carbs into your muscle cells and keep you pumped. This obviously is a good thing because by shoving the nutrients into your muscle cells you are providing the fuel needed for hypertrophy and, in the case of IGF, hyperplasia.
In summary, IGF-1 is almost as anabolic as insulin. It's safer to use, and does not have the propensity for making you gain a great deal of fat. Unfortunately it's nowhere as cheap as slin, but i'll take a vial of IGF over 10 vials of slin any day. If it makes it any easier, you may want to think of IGF as a smarter, more refined version of slin. Now I don't want to get technical as to how that statement is not biochemically correct per se, but for all intents and purposes, you can take it as being pretty accurate.