Your opinion

Some tab collars have the "tab" close with an actual button, some close with a "snap."  Some tab collars roll like button-downs, and the effect of the roll plus the inward "pinch" of the tab combine for a strange appearance.  If you decide to go for a tab collar have them use firm interlining.  It seems that the purpose of the tab is to hold the tie knot higher and allow it to "arch" slightly.  This could be achieved without a tab if one carefully ties the tie exactly around the collar band and ties the tie tightly enough around the neck so that the knot is not allowed to shift downward.

Other things to be aware of: The tab pulls the top of the collar apart around the knot, even if you use a small (four in hand) knot. This means you have to be extra careful that the collars meet with no space when the button is done up so that it is not distorted. I have one that if I don't tie my tie with a tiny knot, it distorts to the point that the chest of the shirt pulls apart some, if that makes any sense. It's best to try it on or get it made custom and if you buy stuff second hand like me, move the button yourself. Also, the tab collar is necessarily a narrow one, which means that ties and lapels should be correspondingly narrow or you risk looking goofy. Also a slim (not necessarily skinny) tie helps with the size knot that is required. I don't think I've encountered a shirt I could get the tie that tight on in which I also could breathe, but the other option is pin collared shirts. They work similarly to a tab in function but use a pin through eyelets sewn in the inner edges to hold the collar together.