Just received a pristine condition "New to me" 177 Gamo Compact which is a discontinued model which has been updated to the Air Venturi V10 now currently sold at most big retailers, it is the third one in my collection and it cocks easier than the HW75. It is a good candidate for an all day shooting pistol with no fatigue or stress from cocking (like my Beeman P17s which I am unable to shoot all day long due to the effort required to cock them and the loud pop it makes when shot).
I don't like the entire upper half of the Gamo Compact (and Air Venturi V10) are made of plastic. One of mine has a crack in it from use and I expect it to be non functional when it completely cracks. I don't like the triggers and the overlever release button/catch are made out of plastic as well. I bought it because eventually one of mine will be non useable due to the plastic cracking with age and use. I don't think it is made of ballistic polymer but plain old plastic.
Accuracy is typical of these entry level 10 meter pistols in the $200 used price range that can cloverleaf to single one hole groups at 10 meters all day long if you are up to it.
There are no provisions for an optical sight or red dot unless you drill out the plastic and mount a rail but that will weaken the structural integrity of the plastic top portion of the pistol.
Factory spec. states 400fps which is only 10fps slower than the HW75 but the effort to cock the Gamo Compact is significantly less than the HW75.
I took a handful of plinking shots at bottle caps at 15 and 20 yards and no problems hitting them consistently using Crosman Super Match Wadcutters and RWS Meisterkugeln wadcutters.
Trigger is not as crisp and light as on the HW75 and feels a little better than the Beeman P17 out of the box.
If you can find one at a good deal it would be worth it if you want an accurate target pistol to plink all day long but be mindful the top portion where you exert pressure to cock it on the closing stroke is plastic.
I think the HW75 is worth twice the cost of the Gamo Compact or Air Venturi V10.
There is a night and day difference in build quality between the German and Spanish pistols.
The Gamo made pistols can hold their own against more expensive target pistols IMHO.
I surely can't say that about many other GAMO guns I have shot though...
HA