What your dress code is also sets how you want to look as a company. I would presume that many investment banks are on the more formal side of dress -- partly because formal clothing tends to cost more and banking is a profession which wants to see itself as cultured, upper class, and wealthy.
However, I would ask if you have worn a nice tailored suit. It's really very comfortable. The quality of the material is pretty far above what most casual wear is made out of. The main cost seems to be in the time getting dressed in the morning and the extra care needed to not damage your outfit, not necessarily in comfort.
That said, I personally hold my own style to a little higher standard than many tech companies (generally long pants, collared shirt, closed-toed shoes).
It kind of depends. I see nice clothes as a way to win customers; if you are not customer-facing, then you need to wear what lets you do the job most comfortably. You don't want to be pulled out of the zone because your suit is too hot.
I wear jeans and a t-shirt and keep a sport jacket in my cube's closet. Then I can be dressy if it's needed for some reason. (I stole this idea from Larry David in Curb Your Enthusiasm. :)
However, I would ask if you have worn a nice tailored suit. It's really very comfortable. The quality of the material is pretty far above what most casual wear is made out of. The main cost seems to be in the time getting dressed in the morning and the extra care needed to not damage your outfit, not necessarily in comfort.
That said, I personally hold my own style to a little higher standard than many tech companies (generally long pants, collared shirt, closed-toed shoes).