We've had both types of panniers - Touratech and Jesse Luggage - installed on our F650 Dakars for a RTW trip. I ride most of the time with Touratech and my girlfriend with Jesse. Overall we both clearly prefer Touratech for long-distance travels - and we think it would be especially true if you travel solo. Traveling as a couple, we ended up leaving on the Jesse bike all the stuff we don't need every day because it was more of a drag to get to it. I marked below the pros (+) and cons (-) of each brand.
(+) Accept inner bags: much more convenient to load/unload
(+) More secure and convenient locking system
(+) Really waterproof out of the box
(+) Better mounting system
(+) Can use the suitcases and lids as seats, tables or trays when camping.
(-) Slightly larger than handlebars (or seems like it). It can be a problem sometimes to slalom between cars or park the bike inside a hotel.
(-) Watch out your feet when pedaling in sand
(+) Narrower (you don't have to think about it twice before sharing lanes in stalled traffic).
(+) The cut-off corners are safer in sand.
(-) In the model we bought (2001) the mounting system does not distribute any weight to the passenger footpegs. Almost all the weight is anchored high and back on the bike. In my opinion, this is a major flaw! The fully loaded bike doesn't behave quite right when leaned. We also broke the rear-shock twice on the Jesse-equiped motorcycle (even though it had less weight that the Touratech's) and we suspect the distribution of the weight to have played a role in the problem.
(-) The Do-It-Yourself part is a bit of drag for such an expensive system. If you don't do it perfectly, the suitcases leak (and the leaks aren't easy to find). The suitcases themselves aren't easy to mount/unmount (although you don't do that every day or even every month) because the rack and the locks can go off alignment and turn rusty.
(-) The locking system sucks. Both the locks and the keys are flimsy.
(-) The weird shape of the suitcases doesn't allow you to easily load/unload what you need. Items at the bottom are difficult to access.
As for the resistance, it's difficult to tell which one is better. Jesse indeed _looks_ stronger but in practice, we haven't noticed much of a difference. The Touratech system might be more likely than Jesse's to loose some waterproofness after a really hard crash - although I'm not talking about the normal off-road crashes (which we had several times) but the "drunken driver rams full-speed into your parked motorcycle" type of crash as it happened to us. Jesse got some cracks on a normal crash once, though, instead of bending - but it was easily fixed.
Voilà. Hope this helps...
Pierre (& Merritt too)