The differences between the two are fairly subtle
With Pantlaza out, ETB creatures like Ranging Raptors, Thrashing Brontodon, and Annoyed Altisaur become engines of value
Keeping Disk mana up in case of emergency is easy
(Check with your local game store for how to participate with in-store Murders at Karlov Manor events.) Plus, as alluded to elsewhere (and a tip for sleuths out there), the Murders at Karlov Manor Bundle is a product that also contains clues for one of the 13 puzzles in the RavnicaDetectiveAgency.com event
Where are you supposed to even begin
Sure, instant would make it a whole lot better and put any interest left in Terminate to bed but if you really want some instant removal play a Doom Blade or a Lightning Bolt as well, it's not like your ever going to not play the Dreadbore