I always wondered the size comparison, what's your opinion on both Cotay? If I don't like my mini, I plan on trading it in for a rDNA40 myself.
After having both for only a few days, I appreciate both devices and wouldn't want to be without either. That said, the SXMini feels better to hold and fits in the hand much more naturally. That said, the bottom metal edges on the screen side of the SXMini are pointy and I do find myself adjusting my hand position at times to avoid them digging into my flesh.
The VS weighs in at 6.8 ounces (7.4 with the Sharkskin) and the SXMini is 6.9 ounces. The VS feels much heavier to me however...but that is purely psychological as a result of its form factor (lack of rounding) I think.
Both are a pleasure to Vape and feel like premium devices. Their respective buttons are excellent but I'd give the advantage slightly to the SXMini. I prefer the screen on the rDNA40 and the new large font in Right Hand mode is awesome. I love the screen location on the VS (I also own a DNA30) and find it much easier to adjust one-handed.
The finish on the SXMini is more robust and doesn't require any skins...the VS I think needs the Sharkskin to keep its beauty. The VS is a breeze to change the battery (although it becomes difficult if you have the necessary Sharkskin installed) and the 510 connector is far superior. The SXMini is a bit of a chore to unscrew the battery compartment if you don't have a Quarter handy. It's 510 is more finicky than the VS and the best way to set your atty is to attach your atty first and then insert the battery before screwing down the battery cover. Otherwise none of my attys sit flush. I have no such issues with the rDNA40's 510.
The extra wattage on the SXMini isn't that big of a deal for me since I vape around 20-25 watts with my RTAs and 10 watts on my clearos.
Funny thing is that I find myself reaching for the known quantity of my VS DNA30 too...I hope VS comes out with a DNA40.
Feature wise, the SXMini's soft/standard/powerful modes are fun and the memory settings are fantastic. I haven't gotten used to the G-sensor yet and find that I'm overcorrecting...but ease of use should come with time and familiarity. As it stands now, the VS is simpler to use (maybe because I'm more familiar with it).
The SXMini is more stable on my desk since the Sharkskin on the rDNA40 makes it a bit wobbly.
These are just a few early observations. I think you'll like the SXMini...my biggest peeve with it is the 510 connector and how you need to get attys to sit flush. If I had to choose only one I'd likely have stuck with the rDNA40, but now that I have both I wouldn't ever (at least until the next greatest thing comes along) part with either.