Haha, split down the middle! So, I bought both paddles just to compare them in the flesh, as I couldn't get to the shop. I can still ship one back if unused.
I took some pictures comparing to may current main paddle, a Red Paddle Co Carbon 100 (525mm?). Still no further in being absolute which size to go for (sigh). The Lima M looks small in comparison to the RPC, but technically has more surface area (534mm?). The Lima L looks much more comparable in size to the RPC, still slightly smaller in the width and much fatter in the neck (564mm?).
Goal is the same, would like to paddle more efficiently/easier, get more distance on either my 12'6 or 14' touring boards. Typical session is distance paddling (10-15km), fitness/recreational touring (like a hike at a steady pace).