Small Wing Paddle

Hi All
I am a 5'6" 160 lb (ish) weight training male pushing 50. Currently I use a club Epic mid wing. I prefer a sustained moderate effort over ~20 km (hopefully longer for this season) and at times I think this paddle is too aggressive for that. Tried a friend's small wing and loved how nice and easy it felt. Haven't used it more than a few minutes so no idea of speed difference. That paddle had really small 700 cm2 blades (my friend is a petite female).
Anyhow. It'd be nice to have a smaller bladed cruiser paddle. My mid wing is 750 cm2. What I can easily get my grabby paws on is 700, 720 and 735 cm2. I have no idea how much difference each step makes. I.e. would 735 be a tiny difference compared with 750? Which size is a reasonable considering it's expected to be specifically a distance paddle. And just to set the right context, we are not talking about big downwinds bit rather rhythmic distance slog in flattish water.
Also these other paddles are full carbon and therefore lighter. 

SpaceSputnik,

I paddle and race with an Epic club carbon small midwing. I think it's great for the type of paddling I do. I used to paddle my sea kayak 10-20 miles per day. I alternated between a Euro, wing, and Greenland paddle. Loved the wing the most. The small midwing allows for plenty of speed without overdoing it. The large and regular midwing might be fine for shorter races or sprints. Most races I do are at least 10 miles. If you can borrow one and compare for your typical paddle distance you might realize a difference. Best of luck. 

My first wing paddles was the Epic mid and small wing maroon shaft. After a couple of years and many many miles of paddling I aggravated my already bad shoulders. I sold the Epic's and bought Jantex flexi-soft 700cm and 720cm. Upon switching, and paying more attention to form I rarely have sore shoulders anymore. Now, I mostly use a Braca XI Van Dusen extra light 705cm, 19k more flexible wing. The 705cm size is great for training,  and marathon racing.
Sometimes less is more!

SS, I weigh same as you, and use and use epic small mid at 735 cm for training and racing all distances.  Makes a big difference in being able to keep the rate up.  If you are just cruising around at slow pace, I find the bigger paddle sizes are fine since you're not loading it up with force but when you are trying to maintain a cadence or (god help you) go upwind, the smaller blade is great.  I haven't tried to go smaller.

When I was less experienced with a crappier stroke, it felt like I wasn't getting enough bite with smaller blades, but now that is a non issue.  If I cavitate, it's because I'm blowing the stroke and it's actually a nice feedback mechanism.  The classic blunder, for me, is cavitation at the back of the stroke when going upwind or powering up to grab a bump.  Means I've allowed the blade angle to go too far past vertical, carrying it back to the hip.  Sometimes this happens as I get tired, because the body tries to trick you into doing less work, and hitting a proper catch/getting out early feels hard!

Thank you everyone for confirming my thought process.
Sounds like 735 or 720 are reasonable sizes for me to go with. Unfortunately I can't realistically borrow someone else's paddle it'd have to be a guess. My gut feel is that smaller is better which makes 720 is the most likely candidate.

I have always preferred a smaller than recommended paddle. I have a 730cm small mid and will buy an even smaller one for my next paddle. I think im going for 680-710cm for the next one. I have bum hands that get sore quickly from larger blades. Also, I find it easier to maintain cadence late in a paddle or race with a smaller blade. 

45% of people in the survey report using a ~730cm paddle, so people split pretty much 50/50 between small wing and medium wing. I dont think you can go wrong with a small-mid as you suggest.