--depends on what you mean by ultralight
--If you mean weight of gear.. low profile reel, specialty thin diameter line, sensitive tip rod with some bottome end backbone vs slow action rod with no backbone.
--It is possible to get ultralight equipment sensitive tip with enough backbone and a pleasure to cast all day.
--Going fishing for an hour or 10 hrs per day, a few ounces, castablility and balance makes a difference.
--Willingness to give up a larger fish... lighten up, shorten up on leader to allow for break away
--I use thin diameter specialty lines thus can crank up on the # test... biggest limiting factor I see is the reel... lighter line, cannot afford o have a reel that isn't smooth or with enough consistant drag available.
--Ultralight can be ultra expensive if you want to effectively take on bigger critters.