I have been thinking about a monolithic upper like the ones coming out from Mega for my next AR build. I can see the advantages to this type of configuration, but are there any negatives?
I had an LMT MRP, and I really liked it. Downside to that platform was the proprietary barrels. Vltor VIS and Mega do not share that problem though, but like Pax said, they are not cheap. Depanding on what rail and upper you were to buy otherwise, thaey may only be a little bit more.
Yeah when you run the numbers it is not that far off from a billet upper and a good quality FF handguard. I thought it was pretty cool that the Mega will accept both DPMS and Armalite pattern barrels.
They are also a bit heavier than conventional. With that said, I love the VLTOR VIS I have and would buy another if I was constructing a long-range precision AR. No need to have one on a carbine however - weight and price don't justify one.
VLTOR describes their VIS as polylithic. I have two of them and you can clearly see where the upper and handguard are attached. They are still great uppers though. I have a noveske en route with the SWS rail and MUR upper so it will be interesting to compare that system to the VIS.