I've experienced the use of 2 geos.
In all GEO's are very light, and very reliable, I have yet to experience any leaks with mine. Compared to DM's they are so easy to maintain (I've owned a pm8) they have very little orings which need care, 4 in total. Just a light lube and its sorted. The gun is ready out the box and plajnet already have it set greatly for you, the use of the vvc is also a good extra allowing you to set the gun as your preferance. The board is great and customer service is superb.
Although the geos have had varying accounts of what people are getting off tanks. Obviously bore, paint, weather etc all depend on your efficiency. My first geo had a fantastic efficiency shooting the same number of pots as a ego. Although my settings were the same on my second geo I am yet to obtain the same number of efficiency. Some people are having issues with the efficiency, although been a front player it suits me perfectly still, so I'm very happy with my geo. I would highly recomend one.