primo is durable... as long as the inside stay dry, it will feed your paintballs. if it gets wet, u get paintball grapes
! no electronics, just wipe it dry and u're good to go. IMHO,if you are planning on getting an invert too, might be better off just getting a used rotor for an extra 20 ish quid more.
personally i'd like the extra 40ish quid headstart in savings on that etek 3. i prefer having an etek 3 with a primo for a few months while u save up for a rotor/prophecy/pinokio/whatever rather that have a invert too for 2 years before getting an etek and then deciding that u are either bored with the invert too or it needs parts replaced. not to mention the money u have spent on batteries. thats me working out the maths. mind you... i've rarely got anything higher than a D for my maths tho...
at the end of the day, its your choice, only u know how u play. i've used the primo on a few tourney guns esp to limit myself from spending too much on paint, and the rotor on a pump just coz i liked how it looked on the gun...lol.