Alright, here is how you should read reviews on this site:
First, disreguard any 10/10. They obviously think that the marker is the best, and never has any problems.
Second, disreguard any 1/10. They are either a) fishing for every little problem, and never even used the marker, or b) enjoy writing fake reviews.
Fianlly, the only thing you need to pay attention to is the "Bad" field. If there's anything good about it, that's great, but it doesn't matter. What you need to look at are the problems the marker has. Desreguard anything like "this gun is teh suck" or "everything" or any one sentance replies. You want details on whats wrong with it. If you are suspicious, check out what the person wrote in the "good" field. Everything has something good about it, but if the author doesn't have anything, lose the review.
Now I'll answer your question. The xtra gets so many rave reviews becuase people are Kingman zombies. They've used one marker, and come to the conclusion that all Kingman are the greatest. Obviously, this is not so. I have never seen any major problems with the Sinister, aside from the usual blowback problems: chops, jams, double feeds, etc. etc.
But if you are going for something ACI, I'm gonna have to reccomend the F4. Great marker there. Has the Sub-Zero valve, sealed cocking, indestructable composite grip, [the new ones] have a very nice stock barrel, sturdy vert adapter, And a spring detent (yes, that's right, a
spring), comes with a trigger shoe, is beautifully anodized (with equally beautiful engraving), uses ss hoses, and of course, it's made by ACI

.
But nothing is without it's flaws. The F4's power feed plug is the biggest son-of-a-***** you will ever encounter. It is damn near immpossible to take out without the aid of pliers. The velocity changer plug tends to eat o-rings when you remove it to clean the internals. The vert adapter has problems with heavier tanks, as it's not an actual piece of the body. You have to tap the grip frame when you go to put the ASA back on becuase the female adapters for the screws aren't an actual part of the grip; they float around without the screws in them. They have the cursed "bullet bottomline." It is the ugliest BL in the world, but it does get the job done. The field strip is possibly the most ungainly (aside from a M98

), and totally rules out cleaning during a game. The air fittings are perhaps too tight.
I leave you to decide what you want
