My husband signed up for Sling and so far he loves it... so much so that he has told me to cut our relationship w/DTV but since they gave me a $35.00 off discount until the end of the year, I'll just hold on.
My husband got orange and blue (or whatever color both packages are) and the epix movie channels for $44.95 a month. He loves the fact he can watch it anywhere and with him having free access to wifi, that is worth it for him. I, on the otherhand, can barely get paper for my office and free wifi will NEVER happen in my time.
My fuzzy math... (okay, it might be spot on)
$12 Netflix
$ 8 Hulu
$15 HBO
$45 Sling
------------
$80
DTV w/o a discount was at or over $100 for a mid-range package and no HBO. It isn't a huge savings but it is just better content and portable.
We also have an OTA that picks up 4, 5, 7, 9, 14, 20, 50 and 66 plus some sub channels in betwen. It is hit or miss with PBS but they have a free app.