Let me tell you the worst thing about this boat. The goofy name greatly undersells its true versatility and ability!
Never having got on with hard shells or wanting to deal with owning/transporting one, after an eye-opening day in Idaho in an NRS MaverIK I realised inflatable kayaks were not necessarily beach toys. After much web trawling I finally settled on a Sunny about a year and a half ago and, for the money and fun I've had with it, I have no regrets.
In that time I've paddled it on flat British lakes, rivers and inlets, spent up to 10 days camping along some lovely French rivers like the Dordogne, Vezere and Upper Allier, gone inshore day-tripping off the Croatian coast 2-up and have plans for some longer sheltered sea tours.
Above all I like the 'air-portablility' (I train or fly to France), the simplicity and speed of the set up and the stability without a seeming payoff with speed. I always feel safe and relaxed which I'd never do (or have done) in a hardshell kayak. Being out in the open and not half-sealed in a hull is agreeable in nice weather and the tough material is confidence inspiring: it loses no air for days at a time. If you fall out or swamp, no drama. Easy to drain in mid-water by just flipping, re-righting and crawling back in.
Like many other owners I originally found Gumboats (I own a Safari too) steered like lilos without a skeg. Nevertheless I found the OE one too deep for shallow rivers and got a batch of low profile skegs made which still worked OK. Then last week much of the Allier in France was often too shallow and rocky even for that skeg so I took it off and hey presto!, managed the next 3 days/60kms in a fairly straight line without it! So, with only a year's practice you can indeed get the knack of skegless Gumboating, although for powering on without resorting to finesse/technique (or on the sea) OE skeg is best as you can put all your energy into simply paddling without concentrating on the continual small corrections. As Christy says, it's a good idea to 'balance' the wing nuts on the skeg and make sure it's lined up straight along the hull. Then if it still pulls to the side you know it's you or the wind or any other number of reasons.
I must say I've never knocked out the seat/footrest plugs, but for a while did experiment with jammed-in tubeless car tyre valves which fitted just right (inflated with a pushbike pump). Could get the seat/etc nice and hard this way but I've since gone back to the simple low-tech plugs which I just pump up by mouth as the hull-spreading effect of these thwarts is not so vital on the wide and stable Sunny (compared to a tippy Safari).
I've toured two up with a 15kg load just fine on class 1 rivers but found that in class 3 it was more raft than kayak. I was lucky to steer it around obstacles and anyway, usually got swamped - actually quite pleasurable at over 30°C! Plus it's so stable it did not matter if I went through rapids forwards, backwards or nearly sideways. You can relax and have fun in this boat, but still tour with the rest of them, and best of all, never have to shuttle back or use a car.
It's fast enough - I average 5kph on rivers with much drifting/resting and have kept up on the Thames with a mate in a Klepper and a Feathercraft (but not so well with a plastic kayak).
I like Andy's idea of only jammed in seats (it's never occurred to me to untie them except to change from solo to twin). They are not the greatest - just ordered an Aire seat to fix against a home-made 'spreader board'. Will add a bit of space too. Solo, I've also found recently the footrest thwart too far away to brace on when trying to 'lurch' the beached boat off a rock in mid-rapid. Hopping out would be quicker of course but I may remove the thwart too and organise another board with a useful Otter box in front to foot-brace on. I did wonder about thigh straps on the Sunny to aid manouverability. I notice the Canadian Innova website recommends them but really I think any boat of 3.9m is just too long for class 3 finesse. Anywhere else it steers fine.
I stuck on some extra, home-made D-rings - keeps the luggage in when flipping it to drain it and in case it capsizes (never happened yet).
Self bailing? I thought about it after all that class 3 swamping (aint tried it in the surf yet) but after looking closely I (being 90kg + gear) would definitely be sitting in/towing water. A self bailer (like a Safari) needs a thick floor to keep your butt out of the swill. But give it a go, bailing holes can be reliably duct taped up for dry, flat-water boating (as I've done on my Safari). My crappy looking Bravo pump has lasted just fine so far too - the yellow hose can split, just trim it and jam it back on to the adapter. I also like the idea of trying that Spirit Sail for a sea trip we have lined up.