If you take care of it a good set will last you forever. I've had my 8" Freud safety set, (shortly after they came out with it) for somewhere around 17, 18 yrs. I use them a couple 3, 4 times a yr., never had them sharpened and they'll still slice you easy.
I've tried wobbles and don't like them, not only are a rough cut but they'll shake a portable TS to death.
There are so many options with a dado that a router can't compete with, depth, width and speed to name the obvious. Add a sacrificial fence to the TS and you can adjust the depth and width of rabbits 2 to 3 times faster than a router. Shelf dados with a 30" or 50" fence will do 5' to 8'4" towers. Add spacers to the cutters and you can cut any width from an 1/8" and 3/16" to 15/16" no problem.
Lastly dados cut glue grooves, show me a router bit that does that!
Never bite the hand that looks dirty!
The more you know the more you're worth