I am busy familiarising myself with the revamped and new storage options going from vShpere v5.5 to vShpere v6.5. VMware Virtual SAN is an interesting beast but would like to know how the real life perspectives are. 
Our current production environment has three ESXi virtual hosts attached to a simple iSCSI storage unit (ReadyDATA 5500). At our offsite, we have two ESXi virtual hosts connected also to iSCSI based storage unit (EMC Clarrion AX4). Our biggest challenge is that cost of storage units from EMC, NetApp and HP are very hard to quantify as we basically just require block based storage which is certified by VMware, good support in case we can not deal with a problem and parts availability for at least 5-10 years.
VMware Virtual SAN seems like a very cost effective option to build reliable shared storage. It also seems that the virtual SAN nodes could exceed basic storage unit by a long shot at fraction of the price and provide more flexibility. I am busy obtaining pricing for some entry level vSAN nodes from Supermicro (5TB) and will also look into what HP has to offer.
I would like to find out the following:

1. Is the recommended two to three vSAN node requirement to be strictly
followed? Can I get away having a two node vSAN for our offsite?
2. From the sound, I can get good performance by having flash
accelerated SATA drives or 10k SAS. We currently using 15K SAS
drives in a RAID10 setup.
3. Did anybody go through an elaborate exercise of converting their
current shared storage environment to a VMware virtual SAN
infrastructure?

I can provide more details - so please feel free to ask.