Easiest way to put things is the Riva resembles the Minikin in size and shape. The Odin is a big mod as it is 21700 compatable the odin shape is nothing like the Riva. I own both mods. If anyone buys and doesn't like their Riva i would be willing to swap my Red Odin especially for a Black Birdy version of the Riva.
I think some folks are either to picky or don't have enough know how when it comes to their cons. Some people even think cheaper boards are as good as a DNA which is actual Bollocks. I for one can tell the difference, the cheap boards have improved from 5 years back but so has the DNA chip we now have colour screen and replay not to mention the chips efficiency and accuracy in TC mode. As a long term vaper nearly 7 years and having tried/purchased a lot of gear in that time. I can honestly say a DNA device is more expensive but you get full value for money and top quality for the money. So for £72 its a bargain, you could pay that for a Smok mod which will either go capput or be worth a fiver next year