I've used several routers on my D4R, but prefer my two 618's in the D handle bases, when making dovetails. I might use a smaller router, if I had any that took 1/2" bits. I have a DW611, a Dewalt Laminate trimmer, a small Makita 1 hp router, and a very old Black and Decker 1 hp, but all of these only take 1/4" bits. I've tried using 1/4" dovetail bits and have not been happy with the results.
After buying a DeWalt 618 three base kit and using it a while, I tried it on my D4R with the fixed base and then again with the D handle base and I liked the D handle base for this use very much. I found that this worked so well for me that when another 618 three base kit went on sale, I bought it. One of these kits is always in the shop and the other is usually in my truck, but when I use the D4R for dovetails I have both kits in the shop and set up with the D handle bases. A word of caution - if you use two identical routers to make dovetails, label them with a piece of masking tape on the top and a bit of art work on it to show the bit shape that's in it. DAMHIKT.
You should also make yourself a couple of platforms about the height of your dovetail jig with a big clearance hole in the top of them for the router bits, so you can set your routers on them when changing the work pieces. I place these little platforms just behind and to each side of my D4R, so I can place the router there when not using it. Straight bit is always on the left and dovetail bit is always on the right (when I'm well organized). Having a platform near and about the same height as your dovetail jig reduces your router lifting requirements as much as possible. If you make dovetails all day, this becomes very important. The first time that I made dovetail joints all day and placed the routers on their sides on the bench, I couldn't lift my arms above shoulder height the next day. I've not had this problem since building the router platforms.
They are just three pieces of 3/4 scrap cabinet birch screwed together to form an upside down U shape, with a big hole (about 1 1/2") drilled through the top for the router bit to hang down through. Nothing fancy or time consuming to make, but very much worth doing.
Central North Carolina