Yeah but, sorry, if you have only played one game in a series and it wasn't even the first, can you really say you can quantify what feels like that game to you?
You might want to change that to, "I prefer the atmosphere to 3" vs. trying to claim it feels more Fallout. 3 is more the outlier on the Fallout atmosphere than Vegas that fits more in.
Also, just cause it was your first doesn't mean you won't find you like another better. 3 was kinda my first (I had tried 1 several times and honestly 1 is probably my least favorite <- not saying I didn't like it, bad game. Just between the four I've played, it's my least favorite. But for whatever reason I really wanted to get into it... to the point that I have bought 1 three times so far because first for mac, then for pc, then for mac with the new OS). It was definitely my first that really had me truly fall in love with the series. And it's not even my second favorite (was until I played 2
).