I've got a Dakota 54 ah, a Canbat 50 ah, and a Canbat 10 ah - all Lithiums.
I use the 54 or 50 ah for an electric trolling motor on a 10' plastic boat (Pelican Bass Raider) Boat & gear & me total about 350 lbs, and I can troll at mid or low speed for 6 - 8 hrs straight on the 50ah.
All of them are less than 2/3 weight of the equivalent lead/acids I used to run.
Because you can run them right down to nothing without harming them, they have just as much 'run-time' as a lead acid with 15 to 25% more ah, where it's recommended that you don't use lead/acid past 75% discharge.
My only concern with lithiums is that there's very little warning that you've run out of juice! With my lead/acid, the trolling motor would begin to lose power, and I'd know it was time to head straight in to the dock. With the lithiums, you have about 30 seconds 'warning', and you're dead in the water! So make sure that your charge status lights are visible, or that you carry a spare. In my case, I run my fish sonar on the small 10ah lithium, and switch the trolling motor over to that to head in - if the big lithium runs out.
I don't see any difference between Canbat and the Dakota, except price. Unless you find a real good sale on the Dakota's (which Cabelas sometimes has), the Canbats are less expensive. Their service is excellent - you can call and they'll answer any question knowledgably, they also have great sales come up on their website, and their shippings reasonable & fast - batteries are well packaged.
www.canbat.com
Once you go lithium, you'll never go back!