I have said it a few times here but I do love my Precision Dogs set. Simple to use and dead accurate. Jerry is a real pleasure to deal with and their products are top notch!
I use the Rip Dog guides and really like them. Haven't done me wrong yet. I think I have the entire rip dogs offerings. I did, however, just order a set of Woodpeck's set since the idea of housing them in a systainer appeals to me. (Mainly for transport reasons).
You can't go wrong with any of them I think. In other words, I don't think any of them offer a feature the others don't have - you won't be bummed you got one instead of the other. They all seem to work splendidly.
In terms of obvious differences, the Seneca and Precision units are aluminum, while the Rip are a thermoplastic (I think delrin). Some people may be more comfortable with aluminum holding up better over time, but honestly I have the Rip and don't have any durability concerns.
I think the more important question is which lengths of Incra T-track plus to get!
I have a set of Seneca ones which work well, however, having just bought the Carvex Accessory kit, I am tempted to buy another core maker KS-PS 400 and make the small brackets for this jig: