As a long standing Fallout fan (having played since the original released in 1996), I can happily say this is the closest the new games get to recreating the original feel of Fallout 1 and 2. The weapons feel like they act the same way, like the player's choices still have the same impact, like the progression still gets absurd at higher levels.
There's many subtle nods to the original design to; bringing back Robobrains so sadly lacking in Fallout 3 and New Vegas, the architecture and building layouts of the original games, the return of the real arrogance of the Brotherhood of Steel, and the desperate hell in the simple lives being lived by farmers and traders.
Even more subtle is the music - so much of it closes in on the original ambience, directly taking certain sounds, riffs and progressions straight from the original games.
As probably the best of the new series of Fallout, it's hard not to feel nostalgic when playing this game, and so I would highly recommend it to any of the oldschool fans, and also rate it high enough that it should be the entry point game to the Fallout franchise for new fans.