Just throwing this out there, I don't own either yet
.. Thanks to Mariner Demo days yesterday, I got to spend time in all three boats outback, slayer propel 13 & slayer propel 10. All three seem like great boats.
It is said many times on here, that you really need to demo as everyone's needs are different.
I am 6' and 215lbs. With a left knee that is picky, sometimes I can ride my bike no issues, other days my knee will hurt afterwards. So the big difference was the force required and motion on the propel unit vs the mirage drive. Short answer for me, is using the non-turbo fins on the outback was much easier on my knee. The mirage drive had me peddling a little faster, but each stroke required less force. So for my body, I would rather spin my knee at a higher RPM and put less force on it.
The other big thing I noticed, is the propel unit's sweet spot was a very very slow cadence. I took the slayer propel 13 out first and found the drive harder to pedal than I expected. It took me awhile to figure out that you really need to peddle slow vs how you would peddle a bike. All kayak hulls have a top hull speed and if you try to go past that you are just wasting alot of energy. I could feel the force twinge my knee a little. Once I slowed way down, like 30 rpms I was easily going 3 mph on the gps.
The outback had the new 2015 stock fins, and I felt I could run it at 3mph easily as well, the motion was a tiny bit more cardo workout vs the propel was taxing my leg muscles when going above 3.5 mph. Trying to go 4.5 to 5mph was alot of work in either boat.
I also have size 11 feet and the bottom of my heel on my sandals would clip the bottom of the kayak or the hook for the bungie on the cover. My sandals are big, and maybe with a closer fitting water shoe it wouldn't be an issue. You may want to try it with summer shoes and winter shoes to be safe.
SEATS : I have a native ultimate now and I like the seat, however the seat in the slayer when mixed with the propel motion was not as comfy on my back vs the new outback seat. Hands down the new seat on the outback was my favorite seat. I really like the height adjustments. Having the option to change the seat angle would be great on a long day on the water and help my back and knees.
Deck Layout : was a toss up. The slayer is clean open, flat bottom for standing and I love all the built in track. The outback has the great center hatch, which I would upgrade to the rectangle one like on the pro angler. I also like the bow hatch was included on the outback. But no track anywhere on the outback and all the cut outs for little cup holders and stuff means you would have to put in little pieces here and there. The new outback deck did keep the water from the mirage drive in it's own well, so the floor by the seat and center hatch stayed dry. The slayer being flat all the way did seem to let water slosh upto the seat area. Native has the center console but anything you put there will have to be cleared away when you have to lift up the propel unit.
Hull Ride : The wind picked up, so I did get a chance to push both boats into some small chop. The slayer hull had a small edge over the outback. I felt like the outback still splash more spray up. BUT the outback tracked better. I felt myself making more rudder adjustments on the both slayers vs the outback when out in the wind 10mph + to 15mph. Paddling was a toss up. Turning with the stock rudders I would give the outback the edge.
Beaching and shallow water : The mirage drive ability to flutter kick in shallow water and fold up against the hull is awesome. of course the propel has reverse. Reverse was cool and I was able to hold the slayer in position better when pretending to fish a fixed item like a stump or bridge piling.
Durability : I noticed some rust on the bearings on the 2014 propel drive they had out there. The mirage drive seems easier to maintain and repair if needed.
Slayer 10 : awesome little boat. the outback sport is to small for a big guy like me. I think that slayer 10 propel is the perfect balance. Stable, not much slower than the slayer 13. I could fit that boat in the back of my small SUV and close the hatch. So no car topping, no trailer etc. I put my 12' ultimate in my SUV now but the hatch won't close and about 1 foot sticks out past the bumper.
I also tried the hobie revolution 13 with the turbo fins, fast boat, something someone should seriously consider if they want to cover alot of ground. Paddles nice as well, new vantage seat is awesome, but just a tad less stable vs the barges the slayer and outback are.
If I had to buy a kayak right now, I would buy the outback. I couldn't risk that much money on the propel drive and my knee. The outback seat was more comfy for me, the mirage drive motion and simplicity outweighed the propels reverse.
NOW am I buying an outback. Probably not yet. I was not in love with the deck layout, the hull slap etc. I am hoping to find away to spend some more time in a propel. I think I may have gone too hard to early on my first outing and upset my knee. Also my knee and legs are not in the best shape, I have not been on my bike in months, so my knee always hurts when I first start biking in the spring. I may try to ride more and get my knee and legs in better shape and then try out the propel again. The idea of being able to throw that slayer 10 in the back of my car, close the hatchback and know it is safely secured, goto work and then after work go fishing is very appealing.
Anyway, just my thoughts ..