I wanted to hear some opinion about this mod. Thanks.

It is not a mod it is a total conversion.

It is the only total conversion for Oblivion that is comprehensive and complete.

If you have played any of the Gothic games and liked them then you will like it. It is very much an attempt to do a Gothic game with Oblivion engine.

Installing it will mess up any current Oblivion game you have. All the answers on how to avoid this are described in http://www.gamesas.com/topic/1305295-nehrim-and-mods-iii/.

"Complete" is a matter of opinion I guess. There's still plenty of stuff that's not done yet in the later stages, but the main quest is story and feature complete even without the 1.5.0.8 update.

I'd definitely call it a cut above normal Oblivion. There's a lot more interesting stuff going on and the world is far more detailed, varied, and fleshed out.

I can't think of any other total conversions that are playable - much less completed.

Sure there is more they could have and should have done with it - same with Oblivion.

Nehrim is excellent, highly recommended. make sure you've got a good system though, it's very resource intensive.

That's not true. Nehrim get installed in a different folder and doesn't touch the Oblivion folder. After installing Nehrim you can play Oblivion without problems.

To be honest, when I installed Nehrim there was only 1 choice: "Install in a separated folder".
I don't know if the "Overwrite Oblivion folder" has been removed or was not available for me for whatever reason.

IMO, Nehrim is 100 times better than Oblivion. I suggest everyone to play it

Yes while it is true that the later versions of Nehrim offer the option of installing as separate from the main game folder - it is still Oblivion at heart and as such it will share the same save game folder and same AppData folder.

What this means is that regardless you will see the same save game files in both Oblivion and Nehrim launchers.

If you use mods with Oblivion or with Nehrim that makes it even more confusing due sharing the same AppData folder. This will result in things like what mods are and are not active being mixed and overridden depending on which launcher/mod utility for whichever game is last active to be the winner.

To truly have a separate game you need to use either mTES4Manager or MOM as recommended in the Nehrim and mods thread.

It's nothing short of amazing and if you don't play it you're missing out on a great piece of Oblivion modding.