Hello MyMikro,
Welcome to Communities and vSAN.
Your set-up looks decent for a lab, but I would agree with GreatWhiteTec that *real* controllers are the main component missing here that would be the main bottleneck - last time I checked the lowest price for controllers on the vSAN HCL is ~$100-150 which is fairly reasonable.
The bottleneck after that would be the cache-tier SSDs as these can be put under a lot of load compared to the capacity-tier (how much more depends on the workload profile).
Whether this lab set-up is a good fit for you really depends on what you want from it - if you want to emulate a small functional Test/Dev environment then this works well, but if you just want to learn vSAN and play with different configurations then I really think nested is the way to go as it allows far more flexibility (and easily fixed destruction!).
You could always have it both ways and use this 3 servers set-up as a physical vSAN to run ESXis on VMs to create more vSANs and go nuts with Ansible!
If you want to dip your toes and see what vSAN is about (or test stuff without much set-up or clean-up) I find HOL to be an invaluable resource:
http://labs.hol.vmware.com/HOL/catalogs/catalog/876
Here are some other great vSAN resources to get you started on vSAN topics in general:
virtuallyghetto.com/category/vsan/ (particularly good resource for Nested set-ups)
cormachogan.com/vsan/
yellow-bricks.com/virtual-san/
Bob