Originally Posted by
robow
I think the stated weights of the Bob Yak and Ibex include the weight of the wheel and tire, but maybe that's not what you intended?
Bob's weight spec is for the complete trailer. BUT, they don't include the Yak Sak, which weighs over 4 lbs. With the Yak Sak, a Bob weighs between 17.5-18 lbs (i weighed mine). A Burley Nomad is lighter by 3 lbs, plus has about twice the volume under the cover that a Yak Sak will contain.
Panniers weigh between 1600-2100g per pair. Racks weigh 1300-2400g for f+r. So, total weight of 4500-6600g / 10-15 lbs. With about 80L volume (a lttle more than yak sak, a lot less than nomad).
Carefully selected panniers/rack will give you more load capacity per pound of equipment than a trailer. However, the decent ones cost more than a trailer, are not as universally adaptable to any bike, and harder to sell. Trailers are a snap to attach/detach to a bike, and extend the life of your wheels (especially the rear) over comparably loaded P&R system. If you get a trailer, it's fairly easy to sell on ebay when your're done with it and recover 50% or more of your cost.
Trailers are a better choice for off-road / rough road conditions, since the constant, high shock from these surfaces can break a loaded rack or frame braze-on rack fitting. The only Yaks I know of that broke were overloaded AND used off-road.
The biggest cost of a P&R system is having a proper touring frameset to mount them.