Definitely some mixed reviews on the SVD, but I've had mine since September and no issues yet.
Not a fan of the VV. My wife has had one since around Christmas time and the battery is already starting to fail. Works fine for a short while, then the battery quickly goes dead.
We do have 3 MVP2s in the house and they are all solid. Simple to use, and a huge battery life. We run Kayfun lites on them with 1.5-2.0Ω coils using 30ga wire and get good performance from them. I take one to work with me for my all day vape because the battery life is so good.
My only personal gripe with the MVP2 being a mech mod user, is the measly 3 amp output limit they have. It would be nice to have a little extra power available, but if you build to suit it, it still provides a good vape with the Kayfuns.