Honestly if you already have a Gateway card I see no reason to not make some use of it. But for me at this point investing in gateway makes absolutely no sense anymore. If you are able to use gateway on your system, then you also have access to exploits that give you the ability to use free community-developed tools to run CFW and install any game you want. Especially with recent apps like freeShop making it easier than ever to download games.
This is just my opinion, but at this point Gateway just isn't worth investing in when free tools can do almost the same thing, and for some things it can do an even better job than gateway.
And with the latest catastrophe that was GW-A9LH (a moment of silence to all the bricks, particularly the New 3ds users) I lose more and more faith in Gateway with their latest software items.
I mean Gateway definitely got the wheels rolling on the 3ds hacking scene, especially with the exploits for 4.5 and lower (mset exploits), but at this point I feel they are trying to play catch-up to the rest of the community.
Edit: Fixing some grammar (you didn't see anything)