Ok, since I'm expected to pipe up here... These are my Personal opinions based on my own experiences.

TANKS:
Pros - Attractive for display and decoration.
Typically more space than tubs, especially height.
Easy to clean/wipe down.
Hold and spread heat well once insulated.
Smaller sizes not too expensive/easily found at sales and online.

Cons - Heavy!
Unable to be stacked without special adjustments
Easily breakable if dropped.
Take tweaking to get things stable

TUBS:
Pros - Lightweight.
Can be cheap $$.
Fairly easy to clean and disinfect.

Cons - Too unstable! Temps and humidity keep shifting.
Ugly! Even the clear ones.
Usually too short for explore-loving snakes.
Not as much overall space (floor is smaller than upper dimensions)


There's my say on things. I'll always prefer tanks and display cages over tubs. Maybe it's just me, or the way we keep our apartment, but tanks hold temps and humidity rock solid here, while tub temps are all over the place and humidity is either too high or bone dry.