1. as for hair dryers plugged into vanity drawers, my concern with that is, you have to leave the drawer open while drying your hair, don't you? That would be a real annoyance to me in my narrow bathroom. I have a single outlet on the wall above the countertop and I find it's sufficient for everything i need.

That hasn't stopped me from lusting over the darn Robern uplift medicine cabinet with more outlets/lights/usb than you could ever dream of, but I can't imagine using those features other than occasionally! maybe someone who has this can chime in.

regarding your 2 nd question-our vanity in the master bath (part of an addition so it was being built) was custom -part of our agreement with the contractor.

It helped a lot when they messed up the framing-and vanity had to become non-standard, narrower and all.

If there were no mistakes-I'd still like the vanity, we had a great cabinet maker.

But it was "a gift" from the contractor so to say, and since I chose wood that was quite expensive and cabinetmaker loved it too, -it was more expensive gift than the contractor was hoping to give))

Then it was additional headache in terms of sourcing slab, sinks, etc. We did save greatly on them btw-but in money, not in time.

Our vanity is really long too. I wonder if we saved on a pre-made one.

Other vanities (hall bath, powder room) are small(one is smallish, one is tiny) and we bought them second hand. Hall bath was the only space we didn't gut (sore thumb..but they recently remodeled so seemed wasteful) and to me didn't warrant anything particularly great. So it's a premade thing with some cultured material on top, I'm not sure what material . and we bought it for cheap on Craigslist. It is standard 36 inch as far as I remember.

The powder room was carved out of some space and had to have a really tiny something inside, and I managed to find on Craigslist something that was custom made by somebody and the family decided to sell it afterwards. Had to be attached to the wall though so the contractor worked with some ironsmith to work out the solution. Didn't cost us anything-but was an additional work etc.

So I guess it depends on a space, The more challenging the room/reno-custom might work better. If sizes are/get to be pretty standard-then obviously you risk much less ordering/buying premade.

PS we didn't want electric oitlets in the custom made vanity, I don't even own a hair dryer. So it seemed like something we didn't really need.

I have outlets in my medicine cabinet and use them for my toothbrush and waterpick.

1) An outlet in a medicine cabinet is fine, although I would rather just have the outlet on the wall since it is more accessible, and having one in the medicine cabinet typically means you have to have the door ajar. I don't find having an outlet on the wall near the sink to be an aesthetic problem. If your wall color is a white tone, they tend to not stand out at all. Here is my bathroom and I think the outlets are rather innocuous, even thought they contrast with the tile backsplash:

2) I'm not a fan of outlets in drawers because they can pose a fire hazand and many of the installations are not code compliant because you have a cable from the wall to the back of the outlet that is continually getting flexed and can also get pinched by the drawer action.

As to custom vs premade vanities and counters, it depends on the function your are looking for. We did stock vanities and custom tops. Stock tops wouldn't accommodate the functioning top drawer of the vanity.

I wouldn't mind an outlet in the medicine cabinet, but would still want one above the vanity. Mount it horizontally.