Ok then I will do just that.
The chart below is self explanatory. I will post the numbers and we can discuss the results. The gist of it is that both air rifles are definitely good quality and worth buying. You will not be disappointed with either one.
The Benjamin is heavier and longer than the Gamo. The Benjamin likes heavier pallets than the Gamo. However the Gamo can shoot lighter pellets a little faster to achieve similar energy numbers.
The Gamo is louder than the Benjamin. The Gamo is a mothe@#$%^&* to cock, where the Benjamin is much easier to cock. Then again the Gamo is a little more powerful.
Kep in mind that the Benjamin has spit though about 4000 pellets, where the Gamo has only eaten about 300. With that said the Gamo has loosen up a bit even this early in the game. I remember the Benjamin was a lot tighter when I first bought it, but not as hard as the Gamo. I assume that the Gamo will get even better with time as well as I expect the velocity shown in the chart below to increase up to 20% as it brakes-in even more as I use it with time. Certainly a tuning could expedite the process.
With that said the Gamo has really impressed me with its out of the box accuracy, something I did not have in the beginning with the Benjamin, it came later after brake in and lots of cleaning the barrel. Now the Benjamin is very accurate as well. With that said both rifles are hold sensitive,but it seems to me that the Gamo is not as picky as the Benjamin in terms of exact hold placement of my hand. The range of where I place my left hand, when I use the artillery position is not as critical as with the Benjamin. I have a mark on both rifles where I place my thumb and pinky on the rifle just to make sure that I maintain consistency in my hold.
The scope on the Benjamin after 300 shots it disintegrated. So I replaced it with a Leapers which lasted about 500 rounds, then a UTG which held very well and still have. However I wanted a better glass with the scope so I mounted an Athlon Talos BTR FFP and I love it.
The Gamo I am still shooting with the stock scope that came with it. It seems to be holding up fine so far, but the reticle does not have mil dots, just a plane Jane. So I will probably go with a UTG or another Athlon scope ( really like the Athlons and seem to take the air gun beating well). The Gamo scope is finicky with holding zero you have to reset if a few times, but once it is set do not move it and leave it there, otherwise you will be chasing your zero and missing shots. Do not expect much from the stock Gamo scope, but once you set it will do its job reasonably well from 10 yards to about 30 yards, after that you will have to guesstimate the hold over as you do not want to mess with the turrets because you will be screwed. So buy another scope for the Gamo if you expect more.
The Gamo is easier to carry around as it is lighter due to the composite stock. I like that it is lighter as it is practical, but it feels cheap to me in comparison to the Benjamin stock which is of great quality wood, but you pay the penalty of weight.
So with that, enjoy the chart below and feel free to fire away any questions you might have.
