In my recent data centre network redesign project I used Cumulus Linux on Open Networking switches from Dell (S3048-ON and S4048-ON). I heard from Cumulus Networks around 2 1/2 years ago and did some testing with the VX appliance back then but I was waiting for the official release of the VRF feature. Ones I got the go ahead for the data centre redesign project, it was clear to replace Cisco and use Cumulus Linux on the all the data centre switches.
I was one of the first Cumulus users of finding a bug with VRF in Quagga because of extensive use of VRFs:
RN-518 (CM-13328) - Quagga sometimes installs a duplicate static route After a Cumulus Linux switch with VRF routes installed was rebooted, the VRF routes were present in the kernel but not installed into hardware. Restarting Quagga resolved the issue. This issue has been fixed in the update to the 3.1.2 repository.
Like in my latest post the idea was to use a converged network stack which needed some more advanced configuration on the switch itself with different VRFs to split the data centre into Corporate (office) and Production.
So far I have a very good experience with Cumulus Networks, the support is awesome and very skilled!