Which one is better ?

They are probably both good reels.  What I can say is that I have a 2500 Nexave that I've been using for the last 2 years and it has given me good service without any problem.

I have a 2000 and a 2500 Revros. I gotta be honest. There is nothing about these reels that I do not like. Not even factoring in the purchase price. They are great reels. 

My recurring comment on these entry-level reels, Shimano sells smooth, and Daiwa builds tough.  

I bought my fishing buddy a Revros and so far so good.  He likes it and has caught several fish without issue. It seems smooth enough and has been a solid performer. 

 

I will also say the same thing @bulldog1935 said above.

 

8 hours ago, bulldog1935 said:

My recurring comment on these entry-level reels, Shimano sells smooth, and Daiwa builds tough.  

 

I have the Nexave 2500.  I love it.  The only thing I would change is that it lacks an AR switch.

30 minutes ago, bp_fowler said:

The only thing I would change is that it lacks an AR switch.

That seems to be the way things are going - more manufacturers are removing the A/R switch. I think Shimano started it - and the newer model Pflueger reels are also now without it.

I can't comment on the Shimano Nexave. I have handled them and they seem good. I do have a 1000 size Diawa Revros. I've been using it for two seasons now, and no problems. Good reel for the money.