While this mod is great, I'd recommend playing Fallout NV on it's own first. TTW can ruin pacing and when i played it (admittedly close to a decade ago) I had quite a few near playthrough-ruining bugs.
Sounds like it preserved the core authentic experience then.
F:NV was the better game, but even as a huge NV fan, exploring post-apocalyptic DC and its suburbs was way more enjoyable a locale than exploring the nuked desert. This gives the best of both worlds.