Yeah the graphene comparison is spurious, except that it's a wider audience article and graphene has been getting inexplicably large amounts of press recently.
A fair point, but I still don't excuse them for being part of the graphene press problem instead of the solution.
As for the other comparisons: what's the maximum speed of a MOSFET? You can get silicon BJTs into the hundreds of GHz, but I'm not sure about MOSFETS
Maximum published speed I've seen for a Si N-MOSFET is around 450GHz at 32nm, not sure of the best reference but here is a non-peer-reviewed one I quickly dug up: http://www.intel.co.kr/content... obviously as this is silicon the voltages are extremely low so it can't do much in the way of power but people have made circuits in the 100GHz range
And as for advantages over Group III-V transistors: it works with silicon which is less faffy to work with than GaAs for example.
GaAs is still in play because it's the most mature III-V technology and is capable but application space is being taken over by Si, GaN, and InP so it's not IMHO a great point of comparison. The nice thing about vacuum electronics is that it doesn't require a III-V material which may make for easier integration with CMOS, though there are groups working on III-V CMOS integration. And I don't think there's that much advantage to it being on Silicon, most wafer fab tools can handle a variety of wafer types, the processes are not so different, plus GaN-on-silicon is being produced though it still isn't quite as good as GaN-on-SiC for example.
The full article doesn't actually make a bunch of wild-ass claims and is pretty good. They're not making lots of OMG YOAR NEXT COMPUTAR SI TEH VALVES!!11 claims.
The description of the technology is well-written. But I can make any technology look good by simply not comparing it against the best of its competitors, and outright mis-reporting the capabilities of the technologies I do compare it to. Just because they're not as bad as,many "2D" device papers out there doesn't mean they should get a pass for being deliberately misleading.