The mini is the way to go if you don't have a need for a full size bike, have to mix your work commute with public trans, need something to scoot around town when walking is too far (and need some cargo capacity), or limited on storage at home or vehicle.
Recently purchased a Rad Mini. I am a full time RVer. Folded, it fits in the back of my Fiat 500 tow vehicle. I have ridden it on packed dirt, gravel, and paved trails up in Idaho and Wyoming. I do a lot of beach and desert camping, so I am looking forward to using it in sandy conditions. The other day I rode from Jackson Hole to Grand Teton NP and back. Still had over 1/2 of my charge left. At 59 yrs old and female, I lift it with no problem, but it isn't light. I remove the battery for loading and unloading. I do have carpal tunnel syndrome in both wrists, but the seat and handlebars are easily adjustable and I am comfortable. Having tons of fun!
I run my Radrover in Sandy conditions sometimes and keeping the PAS in 3, good pedal effort in 1st or 2nd gear, keeping the tires straight, keep my speed up, and a few hits on the throttle can get me through most sandy conditions. Moist beach sand shouldn't be a problem. Extremely loose, hot, dry, and +3 inch deep sand still kicks my butt every time. The 4" fat tires do ride through sand a little better if you lower the PSI in the 10-15 PSI range. I just keep it around 20 PSI because I have mixed terrain from paved roads down to sand on most of my rides.