Migrating VM's from Server 2008 R2 to Server 2012 R2

Hi everyone,
I am in proccess of migrating two node cluster(2008 R2) to new cluster (2012 R2). Now both cluster are up and runnning, everything is fine. I have a question though. I have all production machines still on old cluster(2008R2), and I don't want to migrate all VM's on one CSV at the same time (Because Cluster Migration Wizard will require all VMs on that CSV to be migrated).

Other option is to (and can do it one by one) :
1. turn off VM
2. stop Hyper-V Virtual Machine Mamagement Service
3. Copy VM folders to new server
4. Import VM to new server and cluster.

Has anyone did this before? I know both options will work, just want to know what are your experiences .

Thanks

Filip