Sleep is still a useful spell but you have to consider how easy it is for enemies to wake each other up. Use it in situations where they are isolated. If you put an enemy to sleep, it misses it's go and another character has to dash to reach it before waking it up then you've done pretty well for a level 1 spell slot. Alternatively it is useful to end fights.
As for jumping yeah, it's kind of bizarre jumping is actually FASTER than running. Difficult terrain is scarcely a thing since enemies just jump up over and aroud it.
