It's also 35% more expensive per Gh/s too.
SP20: $1,190.00 + $300 PSU for 1.7 Th/s = 0.88 USD per Gh/s
SP35: $3,920.00 for 6Th/s = 0.65 USD per Gh/s
The above prices don't even include the $115 shipping fee. Face it, the SP20s are terribly priced. S3s and Tubes offer far better value.
When will you state your AM affiliation in your signature? It is fair for everyone to know, just like they see in my signature my affiliation to SP-Tech.