Having two add'l inches beyond the usual 1" overhang doesn't seem a significant difference to me. However, you might consider cutting a width of cardboard 3" wide x the length of your vanity and tape it to the edge of your counter. Eyeball it for a few days and see how you feel. If feels like 3" is too much overhang, you can always have a fabrication shop adjust it.

Runner1011:

You certainly can pull the cabinet away from the wall. Just place a shim on the floor in the back as thick as the tile to make up for the thickness of the tile. Set the cabinet on top of the tile and shim.

Hot melt adhere some blocking to the wall studs and screw your cabinet into the studs through the blocking.

Functionally, where it might affect you is if you have top drawers, you'll lose a few inches of drawer access due to the additional overhang.

Right now you have 1/4" overhang and you'll be going to a 3" overhang. Open your drawers fully. Then push them in 2-3/4".

That's what you'll have. But your question was about aesthetics.

Aesthetically, beauty and a sense of scale is indeed in the eye of the beholder. To the typical person a 3" overhang of a 3/4" thick top will be excessive, because visually it's more than we are used to. Certainly do a mock up, and if you like it, well there you go.

I don't know what the design of your cabinet is, but typically the more overhang you have the thicker you want the top to be. You could make the top "visually thicker" by adding some trim under the top, where the overhang meets the cabinet face frame. Again, that depends on the cabinet design.

Lastly, could you stand for your vanity top to be a bit higher? If so, then you could create a "new top" that extends, say, with a 2" to 2-1/4" overhang beyond your current top, and make it 1-1/4" to 1-1/2" thick. On top of that would go your new stone slab. Sort of like this:

The new top could be painted to match and blend with the color of the stone slab.

Also, look at the type of edge treatment because they will look different - not just design, but the amount of presence they give. They will also feel different as you lean into them. Most fabricators have samples that you can check out to take home and try out.

Here is a link that might be useful: Granite Edge Treatments

I am neither a tiler, a fabricator nor whatever it is Anna is (from posts on here she seems to be an expert in bathroom construction), I'm just a long-time homeowner, and from that perspective, yes, I think having a 3" overhang would both look "off" and would make drawer access very difficult.

(Sorry for the hijack runner101)

"I am neither a tiler, a fabricator...I'm just a long-time homeowner..."

sjhockeyfan, I can tell you what you will be. On January 11th you'll be a very sad hockey fan. lol

Very funny mongoct -- we're going to that game, so I hope you're wrong!

I'm hopeful, but not terribly optimistic. The B's are hurting. Chara and the defense are limping. Rask (goalie) and a few others are getting over the flu...nag nag nag. No whining, it is what it is.

This will be a very tough west coast swing for the B's, three tough teams.

Hoping for good games though.

I like mongoct's idea of raising the counter a bit and using a crown type molding to support the extra overhang. I think the plus would be that the cabinet would look more ornate and higher-end. We remodeled our bathrooms and our vanities look more like furniture pieces, and have moldings and such that have a similar build-uplook, and I love them! However, I personally would not like a 3" overhang without some kind of visual buildup. Also, I have worked in homes with different counter heights, and some lined up perfectly with my hip bone (ouch!) so I would also be weary of that depending on the layout and how tall you/the counter are. It's your home though, so do what makes you happy! Good luck.