This is an old topic but I signed up to 'report' about N5. I have been using the N5 for about two weeks now and games run on it great but with bearable flaws. Mine's the 1.19 version and you have to wait for like 2-3 seconds for the Interface to appear. I've tried several recently released games for it and it's just fine.
Here's the list of games I tried:
The World Ends With You - There's a problem with the background music but game still runs smoothly. The problem with the background music might be the rom's flaw, though.
Professor Layton and The Curious Village - game runs perfectly.
Final Fantasy IV - game runs perfectly.
The Legend of Zelda: Phantom of the Hourglass, FFCC Ring of Fates, Ninja Gaiden Double Swords runs perfectly. I'll be trying more games and will report back. N5 is really not that bad.