It isn't bad, but like others have mentioned, prep work is important. On a v-block they often will not set perfect out of the gate, so make sure it does before you bed it in. If it is sitting slightly crooked or off center in the stock fix that before you you bed it to that off location. Modeling clay works great for filling any holes in the action you don't want the glass getting in (trigger pin holes, etc). Also, I would not bother with more expensive aerosol mold release agents. Johnson paste wax or neutral shoe polish put on and buffed off works just as well (or better). Paste wax will fill any super small scratches in the action and leave a perfectly smooth and shiny bed job behind. It takes a bit longer in application than just spraying on, but it is cheaper and I think gives a superior end product.
While you can clean up a bed job with a dremel, I would not recommend that course unless you flat out don't care what it looks like. Ideally access to a mill would be best, but if I did not have that I would use sanding blocks on the final show lines vs a dremel, though the latter would be ok for removing the bulk, just don't touch the final line.
Of course that last part is easy for me to say as I have access to all the tooling to make it easier and i am sure a customer would (rightfully) lose their mind if they got a new rifle with a bed job that had been cleaned up with a dremel. However, even if it was my own gun and I didn't have any mills to use, I would figure out something other than a dremel for final clean up.
