New Vegas is good, so if you are on the fence, just do that. They have no relation to each other outside of the engine. There are well developed mods that improve various things too; at least that's what I have read but I've not played any. A replay of New Vegas with mods is on my list too, but I never seem to find the mood for it.
Oh, weird. I don't see the point of that; it sounds gimmicky in order to sell yet another version of the game. Like how they keep finding a way to re-release Skyrim every few years.
It's a mod , I've been meaning to try it out for a while. You have to own both games and all DLC to even install it. Not sure if the weapons / armor / etc carry over or not. Anyhow I wanted to replay NV again and realized it's been forever since I played F3. For some reason F4 never resonated with me but I really liked the first 4.
Ah, after reading the FAQ for the mod it makes a bit more sense. Putting the NV mechanics onto FO3 would be helpful, if you like the FO3 vanilla game. It doesn't go into all the changes but they say they have changed both games to make it seem more like one game, but Bethesda's writing is bush league compared to Obsidian, so I would think it jarring to move back and forth.
Well in fairness, the NW games were clunky when they came out originally. I got into them a lot but that was more the EQ group I played with all play a module together than the regular game. I do recall one of the modules (I *think* it's mask of the betrayer) being really really good though.
The campaign is not designed to be very hard so you'll crush it with any solid build. The AI isn't really smart enough to attack your terrible will save but boy howdy I remember there being an optional dragon fight very early in HotU that gave me fits. Honestly not sure if scythe WM is better than scimitar, you do put out absolutely hilarious numbers but so much of your damage is overkill most of the time.
NWN Blademaster build in Tides of the Underdark was busted as fuck I remember that. I don't entirely remember what I did but I had a bunch of parrying stuff so I could pretty much infinitely parry/riposte everything and just wrekt shit.
Ackchually I'm so rusty I forgot about cleave/great cleave heavily favoring 2h weapons so the "wasted" damage from overkill doesn't matter near so much. Scythe does make for lulzy numbers but for overall damage output greatsword is right behind, doesn't require a feat for exotic weapon (not sure if this really matters for a 3rd edition fighter), and will be less streaky due to the wider crit range. Any properly built weaponmaster will trounce the campaign, it's not balanced around optimized characters at all and 3rd edition was very power-gamable.