That was the exact issue. There are 2 ultimate packages. I asked for 150/10 and was offer it for $75 after 25% discount. I finally got a rep that figured it out and changed me to the correct 150/10 package and I then got the new correct speeds. I then got an email confirmation:
Remove ultimate $99.99
Remove 25% discount
Add ultimate $122.99
Add 25% discount
Called retention to complain, they told me about the 2 packages. I told them I needed the fast upload speeds for the $75 quoted price. The rep switched me back to the $99 package and enabled the fast upload speeds. At last check, I was still getting 150/10, even after reboot of the gateway. Never got another email confirmation, so will need to confirm the pricing.
I also enabled bridge mode on the gateway, hooked my own router, tweaked the MTU to a lower setting (1450) and the Slingbox connection has been smoother across the pond.