I have been in the airsoft world for around 5 years. Not the most experienced when it comes to guns, although i have owned a few.
My most recent purchase was a Lancer tactical M4 (long) RIS version. Out of the box this gun fires pretty hot, around 400(+/-), with a surprisingly good rate of fire for a $90 gun. Great range id say 150- 175 feet with good confidence (.20 gram). with .25g you lose a considerable amount of speed and distance, much more than i would like, but .20g is cheaper and they meet field spec.
Externally the gun looks to be as accurate as any of the other models out there. Everything is plastic. RIS is garbage, its quality is wal-mart worthy... but the rest of the gun seems well put together. No rear sling mount was a real disappointment, but was fixed easily by getting one from summer slaughter 3 from the free bin. Front post sight is possibly impossible to remove without grinding and cutting (i dont want to stress the gun more than necessary) Crane stock is fairly good quality, along with the buffer tube. The upper and lower receiver are all right, everything is where it needs to be. Flash hider seems to be non removable.
I have skirmed and went to events with it, and it seems to be holding up to the $300 competitors alot better than i expected.
Performance: 7.5/10 Externals: 6/10 Practicalness: 7/10
Any specific questions i will try to answer (except internal questions, not too keen on taking working things apart)