Are most people using the Leviton, or another unit? It seems as if Leviton is the only company that makes a 9.6kw unit, and it's on Amazon for $1099. You can get a Schneider 30a for $799. Is it worth the extra $300? My leaf and volt only charged at 3.3, so I feel like 7.2 or even 6.6 would be...