Note that some services double as platforms for selling your cards, streamlining the selling process
Unless you have multiple overlapping buffs, players usually just keep track of buffs in their head
Grumgully, the Generous is probably the most obvious example: we make Spirits, they auto-get a +1/+1 counter, and therefore they'll get more because they're modified
Also, we have other new features in development outside of the trade feature introduced here
For me, Im only casting it with X equal to five or greater unless Im in a pretty dire circumstance, since returning the creature is the more compelling part of the equation
But if your deck is focused on controlling the board and accruing value over time, you'll have more time to play lands and cast expensive spells