No cleanup required is relative.

With a Mafell mortiser the bottom of the mortice isn't flat, if you've engineered your timbers to allow for over boring then there is no cleanup on the bottom. The chamfer on the tennon helps keep the required overbore to a minimum.

I believe the Makita plunges to three slightly different depths with each set of the head so a similiar situation exists, is this correct?

The Mafell will cut right to the critical lines on the ends of the mortice nice and smooth. The sides of the mortice have some chain texture that cleans off in about 20 seconds/side.

@ Daiku,

I think Collin put it nicely. Go read his post again.
And if you still do not believe it go try a Mafell. As I understand it the Makita needs to be clamped to the wood because it cuts with the grain. Therefore you probably want to stay away from your layout lines because of tear out. The Mafell cuts across the grain and therefore does not need to be clamped down and you can cut right to the layout lines. It also comes with different size chains as an option (1.5" or 2" or diffenrent metric chain sizes). There is some tearout were it dives into the wood but that will be covered by the face of the brace, post or beam. Keep the chains sharpened and the tear is very little. Used to work with an really old model in Germany for years. Never needed to repair it or do any adjustments to it. And believe me it was running a lot every day.
As for the clean up. I usually oversize my beams anyway. So if I have to cut a bit deeper so I do not have to clean the bottom of the mortise it will not matter. And even if it needs to be cleaned, I cannot imagine any faster way to cut most of the mortise than with a chain mortiser.

@ Derek,

Mafell gets'r done. $$$$$$$

I do not disagree there.
Yet, for any serious timberframer that needs to get the frames cut as quickly yet acurate as possible the money spend would be recovered with just a few frames cut. After that you'll be glad to own one.
I have cut exactly one small frame with 1/2" drill. That was enough fussing around for me. Now there is only one tool, maybe two that I rip out when it comes time to cut mortises. My Mafell and when needed a chisel. 2min. per Mortise after it's layed out and if I need to clean up the bottom of the mortise other wise 30sec. per mortise. That compared to several minutes of drilling and then clean up was worth the $$$$ to me.

Thanks for the input everyone. If I were in the business, it sounds to me like I would need to seriously consider that Mafell mortiser. But I'm not. I need a mortiser to build some smaller frames before I start on a house. Knowing me, if I bought the boring machine, it would be gathering dust at some point and I'd buy a chain mortiser. So, I'm just going to bite the bullet and buy the Makita. Thanks again.

I don't see the makita being that far behind the mafell....
I cut right to the lines on the sides of the mortice with my makita and chisel the ends, probably a couple of minutes each end....

Another boring morticing thread. I for the most part agree with Mr Beggs. On the other hand I enjoyed the ability of the Mikita over the worn out Mafell which was present in the shop. I still am going to use hand crank machines in the future. As for "they aren't cheap" I have recieved machines in the price range of free to $340.oo, compared to $4000.00 plus, I would say hand crank machines are cheep, underlying philosophys aside. Tim

Inexpensive, not cheap.......

I'm from Canada but currently in the UK and I've been looking for a Chain mortiser. I currently have my eye on the Ryobi CM31 - 110v version. I've used it once before and it seemed like a very acurate and fast tool that is better than the makita and costs less than the mafell. Has anyone used it and would I have to do more than change the plug? Is there another mortiser I should be looking at?