Last fall they offered a discounted Sun pass which is booked in Tango + V and it was around 1100 for 6 credits but you can only use it Tues,Wed,Thur,Sat I think.

If they are introducing the passes at those prices but travel 6 days a week, I might buy the T+ versions. But for the difference of 70$ per segment or so and around 250 per segment and better availability, the regular Sun pass is well worth it.