This is absolutely unwarranted, apples to oranges, but since both cost nearly the same, let's indulge ourselves:
SMArt case is better for direct USB port or Raspberry Pi use; new Silver dongle blocks nearby ports. Using an USB extension cable (preferably with ferrites) is always recommended anyway.
Bias-T is unavailable with the SMArt, which is a solid reason if you want to add an LNA4ALL or other bias-T powered equipment.
Direct sampling is easier with the new Silver dongle, use supplied antenna or wrap wire around antenna screw - done.
Price: Manufacturer pricing, receiver only: $19.95 for v.3, $20.95 for SMArt. Full kits: $24.95 for v.3, $27.95 for SMArt.
Warranty: 6 months with latest v.3, Nooelec SMArt 2 years. SMArt is a safer choice.
Performance: about the same overall, there's no compelling reason to recommend either over the other.
As a present: SMArt wins hands down. Three antennas, looks like a jewel, mount and cable exudes quality.
Personal preferences will decide the "Which one is better?" question. I think the v.3 is fantastic for anyone, a milestone in the affordable radio revolution, and the SMArt is just as perfect - both are unparalelled value for money.