A grand total of three emulators can use dynarec for better performance - one of which performs badly regardless (PSX rearmed), another of which introduces a nasty random crash bug if it is switched on (gpsp) leaving only a single lone emulator with a clear and stable benefits when launched as a cia on CFW (picodrive).
Of all the reasons to install CFW I'd have to say that running better performing emulators has got to be almost bottom of the list (unless you're the world's biggest 32X fan).
Actually, the gpsp bug is not so random from my experience. It will crash the GBA version of Doom immediately every time, but I was able to play Mario Advance 4 from beginning to end when I tested it. There's something the dynarec is failing to interpret correctly. Apparently it's not a very common routine, since some games work fine. What can I say, my DSTwo has been worth every penny. GBA playback has been a non-issue for me since before CFW even existed.
I'm thinking it's probably more a lack of disabling Spotpass and Friends settings that are the cause for these bans than having homebrew CIAs installed though. Sure, theoretically Nintendo COULD check everything on your system every time you take it online. The amount of bandwith and resources that would require would be immense though. It's much more cost efficient to let people rat themselves out, not to mention much more damning catching them in the act. Configure your privacy settings right, and you probably won't get banned. Granted, there's no guarantee the system actually respects them, but admitting such a thing would be grounds for a class action lawsuit. Regardless, it would be extremely expensive for Nintendo to check the billions of tickets installed passively. It's the use they're tracking. So, if you want to be cautious, just disable wifi before running homebrew, and clear the log before re-enabling it. You should be fine. I'd offer to test this theory, but I just don't play my N3DS online enough to validate my claim. Online play is what I have a PS4 for.
Anyway, while I'm not exactly convinced this is going to prevent any bans, it's a good step forward. It makes no sense to continue to rely on *hax exploits to run .3dsx files when you have the system fully exploited. And while Rosalina might have a way to go yet, it appears that NTR's days are numbered now that we can have ARM11 at boot. Though it certainly has had a good run.
Now all we need is a Gridlauncher for Rosalina HBMenu !
I hear you. I'm not a fan of the default menu either. Fortunately, there's no shortage of people out there who feel the same way, including d0k3 (he's probably too busy with GM9 to bother with it, but I'm sure someone will do it).