Leigh - 18-Inch Super Jig (Rating: 4)

I added the Leigh Super jig to my collection of dovetail jigs, which already included a P.C. 4210, and an Akeda DC-16. So based on my past experiences with dovetail jigs, these are the models I will be comparing the super jig to. My first impression was that the jig was very lightweight. This may be a good thing with some tools, but I would rather a large jig like this have some heft to it. The side caps are plastic, which on its own isn't a bad thing, but the manner in which you attach the jig to a piece of plywood through slotted and angled holes is downright rickety. Porter Cable Jigs are the only ones I am aware of that use integral brackets to clamp the jig down to your workbench. Most other brands require you to screw a piece of plywood to the jig for clamping purposes. The integral bracket idea is a better approach.

CLAMPING A WORKPIECE
The clamping bars on the super 18 seem very lightweight, and are prone to flexing. In fact the manual instructs the user to tighten the opposite side of the clamp a few turns tighter, so as to make the clamping bar flex on purpose. The cam locks are plastic, and feel a bit flimsy. There is a great deal of friction in the cam locks, ie when they are tight enough to secure the workpiece, they are very difficult to engage. I feel this is due to the short lever of the Leigh cam locks. Porter Cable jigs have longer levers that are easier to engage. Overall the clamping system on the Akeda is the best.

ALIGNING FINGER GUIDES
Aligning the finger guides is pretty easy with the included square drive screwdriver. The problem is the fingers don't always lay perfectly flat. You are supposed to place one finger on the loose guide finger, and gently hold it flat while you secure the screw. The guide fingers lock securely in place with very minimal pressure. A straightedge across the top of any three guide fingers usually reveals one misaligned by 1/16" or so. The guide fingers are the surface that guides the router, so this translates into gaps in the joints. This was very disappointing to see. I loosened and retightened each guide finger, but the misalignment remained.
By comparison, the Akeda guide fingers don't actually support the router. The jig itself supports the router front and back. With the porter cable you also have a flat reference surface (but no variable spacing).

SIDE STOPS
One important, but often overlooked feature of dovetail jigs is the side stops that register the workpiece against the jig. They should be self-squaring and large enough to easily position the board. This is where the Leigh absolutely falls flat. The side stops are thin plastic, and are too small to reliably register the stock. Any errors here, and you will see misalignment between the two boards in the dovetail joint. In other words the edge of the boards won't align. Other Leigh jigs, and the Akeda use fixed side stops machined into the jig, which is much better.
The PC 4210 failed here as well with a thin stamped metal tab that is not self squaring.
The Leigh Super Jig does have a smart spacer that attaches to the side stops, but it is only used for single pass HB dovetails and box joints. I found it very difficult to remove this little spacer tab. In fact it feels like it would break with any regular use.

FINAL ANALYSIS
I always like to ask people with well equipped shops which is their favorite tool. They have many options sitting there, so the tool they choose is telling in many ways. So I have the Leigh Super 18, the PC 4210, and the Akeda DC16 sitting there at my disposal…which do I choose?
For variable spaced through or half-blind dovetails hands down I choose the Akeda. For fixed spacing HB dovetails I would use the PC 4210. I fear the Leigh will be collecting dust, rather than making dust as I had hoped. This is no reflection on the Leigh D4 series jigs, which use a different construction technique entirely. For the few bucks Leigh saved to make the jig this way, my opinion is that it isn't worth it. If you want the Leigh, go all in and get the D4 type jig. If Akeda ever starts making jigs again, get that.
If budget is a primary consideration, this may be worth a look.