Porter cable Omnijig vs. leigh jig
I purchased the Leigh jig several years ago, my decision was based on the fact, at least at that time, that to make different DTs halfblind, thru, etc. you had to purchase different templates for the Omnijig, with the Leigh, it had all you needed with it. some of this may have changed with the OMJ since.
I am happy with the Leigh, the manuals are very clear, though it does take some practice each time I use it, I don't make DTs that often, so I tend to forget and have to be retrained, but it doesn't take so long now.
I did once try the Woodrat, I had too many problems with it, it is a good machine tho, it was just me.