I am on Tostran and actually quite happy about it. Sure, it is a bit more work than injections but seems to work good for me so far (6 mths). Some of the advantages with gel that I see are the ability to regulate the dosage on a short basis.
For example, on training days I somethines put on a bit extra to get some extra boost. Same thing if I happen to get own time with wife
I also do short periods (say 1-2 weeks) when I double the dosage to put on a little extra muscle.
Overall, I have gained about 8 lbs since I started with tostran, which is more than I have gained in the last 3 years.I estimate all of it to be lbm (might even have droped a pound or two in fat).
Another advantage with gels is that it does not affect your liver. The testosterone is just pure T which is directly absorbed into your bloodstream through skin. When you inject, the T is bound to an ester (cyp, ent or undecanoate if you go with Nebido) and the liver has to do some work to free the T from the ester. Not sure how big of an issue this is though.
I am 48, been lifting weights for 35 years.