I like the Topeak Super Tourist DX with lower rails. I had a chance to use one for awhile on a 700c LHT with a Cargo on another bike and liked being able to remove/install panniers without changing items strapped on the rack unlike the plain platform racks. Only question was that the pannier supports were 3/4" or so outboard of the verticals so the top of the panniers kind of bent down. Not exactly a deal breaker just noticed it. I liked the lower rail feature so much I had a lower bar brazed on the Cargo, I should have got a Cosmo.

The Axioms with the Tubus like seat-stay attachments which protrude lower than the flat strap seat stay attachment and appears to allow more flexing than Tubus or the flat ss strap type. I have an Axiom streamliner on a Cross-check and used ss. straps as it doesn't interfere with the fender as much.

$.02 would be to go with lowrider types on the 700c LHT where you can mount the panniers back in line with the fork. The front platform type exacerbate the LHTs inherent wheel flop.

I started using 3/16" bungies strapped around the bottom of the rack over the panniers and onto the top to compress them when empty when riding to work and shopping but stuck with it when loaded up because it helped to reduce the wobbling of contents.