I have a wall sconce lamp in the back of my rig with 2 sockets for 1157 bulbs (with 2 contacts on the bottom.) Clearly the panels would not work there. So the bulbs can certainly still have their place.
Otherwise, I might opt for the panels in my overheads. Mine are the old, white lenses and you can't tell there's a panel in there. It just lights up like it's one, big light. They look great!
But back when I was in the market, they didn't have the panels with the 1141-sized adapter. So I bought the bulbs. Those you can see through the white lens. It's unnoticeable unless you're looking for it, though.
Of course the benefit of the bulbs is there is no concern of them sticking to the fixture. Some light is lost, but since the background is white, I suspect it's not a ton. But... some.
With free shipping and such prices... I would start with one of each and try 'em out for myself.
Hope this helps.