Take a tour of my Router Tables
Interesting Characteristics
I have three router tables in my shop. Two of them are the typical vertical router mount and one is a horizontal table. You might think this is a bit overkill, but I also have three routers (four if you count my trim router). All are the exact same Porter Cable model. Not that I'm overly enamored with this specific router, having multiple of the same router just makes all the attachments, jigs, collets and baseplates interchangable. Having multiple router tables allows me to setup multiple bits as part of a sequence of milling operations. For example, if I'm making rail and stile doors, I can put the rail cutting bit in one router table and the stile cutting bit in another. This speeds up the setup and milling process. Another example is for built-up moldings, say on picture frames. Horizontal routing is great for tenon cutting, sliding dovetails and slot cutting, just to give a few examples.
Commentary
I have one Router table built into my bench top. Of course to the bench purist this is pure heresy. However, my benchtop is quite large and I enjoy the extra large surface as I'm feeding a piece across the router bit. I typically build large furniture projects so as I'm milling a piece on the router, I would prefer to focus on ensuring the piece is feeding smoothly across the bit without worrying about keeping it from tipping off the end of narrow router table top. My router table's fence is also a major customization from your basic design. I have a fine adjustment control (complete with dial gauge) to fine-tune the fence position. For the horizontal router table, it is a commerical unit from MLCS with a number of my custom upgrades. In the photos you'll see my custom tabletop to hold a miter gauge complete with clamping hold downs. I've also added a beefier baseplate from a sheet of 1/2" thick polycarbonate. The original 3/8" baseplate flexed under the weight of the router.
For a detailed walk-thru of individual workstations in my shop, click on any of the links below.