I have rowed and paddled many different boats as I was a commercial guide for years both, multi-day and one dayers. I cut my teeth on Avons BEFORE they came out with the big tube pro. I paddled Avon adventurers, sotars, momentums, aires, hysides, udiscos, and others that I didn't even know what they were. Personally, I have had small boats, cat boats, and bigger boats.
I absolutely love my 160E. I've had mine for 10 years now. I also have the narrow 14 ft otter which, I also love. These days we mostly do multi-day trips like on the Salmon(s) so I love the space. I could load the boat down with 3 weeks worth of gear (food, beer) like for the Grand, and the boat handles great; It pivots, tracks, and is very predictable. I can't say that when I had a jaguarundii. I have friends who have the aire 156, or the sotar sl and they love their boats. Having said that they never were commercial boaters and didn't have the benefit of trying different make boats. The other thing about sotars and maravias are they sure are expensive! Another friend has a Riken with diminishing tubes. He loves it but the passengers definitely get wet.
I have my boat set with a custom, adjustable 4 bay frame. I sit on a 47in dry box. I carry 2 of those, and a 125qt cooler in the frame. I can and many times do, carry 4 rocket boxes in the foot well on a plywood cargo deck. Outside of the frame I use a plywood cargo deck in the back and a soft beavertail in the front so, I can access the valve if need be. On long trips I generally carry 1 ea 125qt cooler for frozen foods, 1 ea 125qt cooler for veggies and condiments, etc., another 100 qt cooler for beer and other things and a 65 qt cooler for lunches. Additionally, we have the groover and groover stuff, dishwashing kit, extensive first aid kit, fishing gear, repair tool box, etc. If I could handle an 18 footer on dry land like, loading, unloading, etc. I would get 1. The 16 is my limit when it comes to "manhandling" the boat on land. both my wife and I are small. My set up is very flexible. I also bring another cooler frame if I need it. It also doubles as a frame that fits a row of rocket boxes. It all depends as you all know, on how many other boats or boaters with experience, and kayakers are on the trip. If you have kids and/or kayakers, the gear piles up quick.
I had a 15 foot campways river ryder bucket boat back in the day. It was a great boat but I was always over loaded. Luckily, I never flipped that boat as I had gear tied to gear piled high. My narrow 14 otter is another great boat. I would give all of the same recommendations for it as I do for the 160e. I got the narrow because I mainly use that boat here in Montana where most of the water is small. However, it has the length for the Salmon if need be. I have let friends use that boat when we go to the salmon.
The discussion of size ALL depends on your needs and experience. Sure, you can make a tandem IK work but for me/us, I like the full bar, I like the dutch oven deserts, I like the gourmet multi-course meals. HAHA. Sure beats backpacking foods and sips of water.
As far as the rubber goes, I glued on wear patches before I even took the boat out. The floor both, under and over seems bomber. Before I made the cargo decks that fit, gear definitely would rest on the floor and against the sides. Other than staining the rubber there has been no unusual wear. Though I never have had to patch my boat I have worked with hypalon when I worked commercially and it is easy and forgiving to work with.
My recommendation is get whatever boat you can get a deal on. These days, they all seem good. Just get one that is big unless, you only do small rivers or are not going to do week long or longer, trips. for extended camping. if you have kids and a girlfriend/wife you really like and want on trips, don't get a diminishing tube boat. Also,don't get a boat that is too small. You'll be surprised between additional bodies on your boat and their gear, how all of a sudden your boat is just packed to the gills--hahaha. If you are oscillating back and forth on size and trying to decide on "a one size fits all boat", then you need more than 1 boat. Don't feel bad...we have a 16, 14, 12, 2 tandem IK's and 2 single IK's.
Happy boating!