I've had my V5 since about 4 months now, and am excited to see another convert! First, let me stipulate too front I'm not in the same league as everyone else here. Yep, one of those sea kayakers.
I'm not in training, counting calories, or using one of the GPS things to count my fractions of seconds between strokes .... not that there's anything wrong with that. Different strokes for different folks.
For me, its just about being out on the ocean, in a small boat, playing in the waves, going fast when I have the urge, or leaning back, hanging my feet over the sides and bobbing in the waves.
The V5 is a great go anywhere, any conditions, just for pure enjoyment of paddling kind of boat. ... Well, except rock gardening. Stable, can lean it, responsive and maneuverable, as fast as any "play boat" sea kayak, and easy to get back in. Started with a plastic one, just to try it out. Traded it in a few weeks later for a Performance layup.
After years with a number of sea kayaks - plastic, then glass, downsizing in volume after discovering I don't want a kayak for expeditions, giving up on trying to roll (bad shoulder), and subsequently becoming concerned on safety (getting back in, in conditions w\out help, and the weight\transport thing. My last kayak was a Valley Nordkapp LV.
Then I started looking at surf skis.
My first surf ski was a Performance V8. Great boat, but even at that weight, 18 feet is a lot to manage walking around, and getting on\off the car. I sold it a few years ago, but missed being on the water. The V5 drew me back in.
I found a some noticeable difference between the plastic and Performance layup. The weight is a big one, but also the seat and stiffness\preciseness of the hull. With the plastic one, I was considering hip pads to hold me in place, and even a - here goes - back band (yep, bad lower back too). The seat seems more defined in the composite, and I had a sore lower back in the plastic one. Not so in the composite. Felt just like the V8.
Now, on performance, as stated, this is purely for run for me. So let me explain: over maybe 15 years of paddling, I know how long it typically takes me to get to certain places from various launch points. My V8 got me there faster than my Nordlow did. The plastic V5 took noticeably more time than the V8. The V5 Performance seems almost as fast as the V8. Now, that's a function of the engine, so most of you folks would not find this to be the same for you - you'd get more out of the V8 or V5 that I do.
There are amazing videos of god-like athletes in the V5. There are many - most perhaps - who discard it a waste of a good layup because it's not a long, skinny needle, and that's what everyone who picks of a surf ski and wing paddle must aspire to. If ya can't train with it, what good is it??
At first it felt funny in a 14 foot boat. Smallest boat I've ever had. Kept thinking I should have picked up another V8. Almost did - was on the fence. I'm so happy I tried, and stuck, with the V5 Performance.
You mentioned how some boats have that "something special" about them. The Nordlow is one of those amazing boats that comes around every so often. Nordkapps have a rep as being one of the more demanding sea kayaks, one that can go into the most extreme conditions (for a sea kayak) ... but unforgiving. Will toss anyone in the drink - even in flat water - who can't handle nuances of the hull design.
The V5 , not so. Practically anyone can get in one, sit back and sip cocktails. At the same time, like the Nordlow, if can take you as far as you want to go. Well, not racing maybe. But maybe everything else.