I also tie and fish about fifty fifty. I mostly use the unweighted buggers with my full sinking line when I want to get down deep over a weed bed. I feel like the unweighted flies float a little above the weeds and I get fewer hangs ups and lost flies. It may just be my imagination but it works for me.
I use both. Sometimes the bead does make a difference. Sometimes the size and color of the bead makes a difference. Sometimes no bead makes a difference.
I need to qualify that by saying I primarily use WBs in stillwaters and not necessarily as weight. I don't really rely on the bead for specific presentations in specific holding areas.
Depending on the size of the bead, it may give the pattern a jig action... but even that doesn't always matter. I use a medium to large size bead on my variegated black and olive WB and Rocky uses a small one on his similar pattern... we both catch trout. However, the bead must be gold in color, whatever the size, or it doesn't work as well for either of us.
Color can "trump" (no pun intended) action. So I honestly don't consider the bead as a weight factor. Unless you are using a mighty small fly with a mighty large bead, the additional weight of the bead is nomanal... at least for me. I've watched the action of bead-head flies in an aquarium and the bead doesn't seem to add all that much weight to a medium to large size WB if you are matching the size of the bead to the hook size.
On the flip side, I've found that sometimes the fish don't need no stink'n bead... and they won't hit a bead-head WB but will strike the same pattern without a bead. This may occur in open, deep water regardless of any weed beds.
Sooooooo.... for me, I add a bead to a pattern just as I would any other material and not with the idea of adding weight but changing the appearance. I believe that sometimes I'm adding a bit of flash when I use a gold or silver colored bead more than I'm adding weight. I may be giving the appearance of a dark head when I add a black bead that gives no flash. This may be more important for my leech and nymph patterns than WBs but when I use a black bead for a head, it is not for adding weight but for adding a specific color.
I've found that a white WB with a silver colored bead-head is the ticket for one specific coastal lake in Oregon. They will not strike the pattern without that silver bead... and this is the case anywhere in the lake using any version of a sinking line. Also, they won't hit the pattern with a pattern tied with any other color of bead. So this tosses the weight factor out the window.
On another specific lake I fish, the trout will start the season preferring a bead-head and then later on, they want nothing to do with a bead no matter the color.
Therefor, I tie patterns with and without beads. Sometimes the fish prefer a bead-head, sometimes they want nothing to do with a pattern tied with a bead. The answer is to always carry patterns tied with and without beads.
When it comes to adding under body wraps of weight when tying a WB... I don't use any. I've never found the need when fishing lakes. Normally I use heavy wire hooks for all my subsurface patterns and rely more on various speeds of sinking lines then weighting the WB.
I think at one time I used weighted WBs for salmon/steelhead fishing in rivers and in the case of winter steelhead, the additional weight could be a factor. These days, I primarily fish stillwaters so the weight issue is not the same as it would be in moving water.
For fishing (smaller) rivers, I pretty much always add a bead/cone and/or weight due to the fact I'm fishing a floating line and relying on the weight to get the pattern down. Like others have said, it depends on the situation.
this is what I do. I will have some with beads and some with out. normally I am throwing a sinking line so its a bead or nothing. also with my beads I generally use colored ones. like black with a white, orange, or chartreuse bead.