i used the tamiya extra thin cement on my metal gamin and rail golem, very clean. it has a very fine brush and very thin fast cement
only problem i saw was of my own doing, to much cement, it got pushed out and when i pressed down my fingerprint got set in the plastic, not hard to buff out.
i work in a modelstore, selling modelkits so i'm pretty wel versed with all things plastic.
the tamiya cement works sweet on the plastic, the parts are attached to the sprues in inginious ways so when you cut it out, your cut part is hidden in the glue seams. (at least in abaout 90% of the cuts). wich i have never seen before, and i must have seen the insides of 100's of pro model kits)
the only thing i missed (not for me but with younger players in mind) is some of them are a bit puzzling to assemble, a little cheat sheet would be nice, or put pictures how to assemble them on the site to minimize costs
afterwards i assembled another metal mini and i have to say i was minning the plastics