My opinion is that the SVD is a better built mod than the eVic, with regard to materials. They SVD is also more versatile out of the box with regard to battery options. The eVic has a lot of technology packed in, but suffers from some trivial limitations, such as 11W and 5V power and voltage caps, respectively. The eVic can use any 18mm battery size, but it requires buying extra battery tubes.
eVic does a better job with PWM, and at certain voltage settings even offers a flat DC output. The SVD uses 0-6V PWM to achieve its output, and to some this produces a vape that is a bit harsh compared to devices with flat output.
If you're a tech head and can live within the voltage and power limitations, I'd say the eVic is a nice
device. It can give you a lot of data, but in the end how relevant will that information be to you? Do you really need custom vape profiles that skew the voltage of the vape over the duration of your pull? Do you really need how much vape time you've accumulated over the course of a day? A week? A month? If you don't care about any of this, then I'd say you don't need an eVic.
Personally, I would probably go with the SVD... Build quality aside, I just don't know how long the control head on the eVic will last. Will it be dead in 2 years, or keep going? The SVD is using a more simple control circuit, less to break...
This opinion is all based on what I like in a device though... Quality craftsmanship, materials, and durability. Can it survive a few accidental falls during the time I expect to keep it? I just have a feeling that the eVic is a device that could suffer a catastrophic failure if it landed the wrong way on a sidewalk... Where the SVD seems like it can take a beat down...