3.7 with a LR is made to simulate HV and it's as close as you're going to get at 3.7 but there are differences. In general the coil on HV attys are more robust and last longer. HV with a high ohm atty also pulls less current from the battery so you'll get better battery life, assuming we're comparing the same
batteries, this also contributes to the atty lasting longer. Also you don't need to take as long of a hit to get the same vape. At 3.7 it can take very long drags to satisfy me. At higher voltages I can get the same effect with a much shorter draw, about the same as a normal cig in many cases, this also contributes to longer battery life due to not holding the button down as long for each hit.
Due to the higher voltage the vape will be warmer and you'll get more of it as well as TH. Lots of people find they can lower the nic level at higher voltages due to getting more vapor with each hit.