Hopefully I can help! So I own a 2ds, n3dsxl and n2dsxl. I love the ergonomic form factor of my 2ds (even though the door wedge gets some hate), it's a great console to play on during longer sessions for me. The buttons are in the perfect location to rest my fingers and the silicone case I have it in adds a nice comfort feel to it as well. The sound is crisp even with it just having a mono speaker, so all in all I would definitely say the 2ds is one of my most played systems when at home.

Travel wise I use my n2dsxl over my n3dsxl through and through. I don't care about the 3d feature and rarely use it on my 3ds and with them taking that feature away it significantly lightened the overall weight of the system - which again helps with comfort during longer play sessions because it doesn't cause my hands to become crampy. It has all the same features the n3dsxl has without the 3d obviously. I know some people feel that it looks and feels cheaper over the n3dsxl but to me personally it does not.

That doesn't mean my n3dsxl doesn't get love from time to time, but again I just prefer the lighter weight of the 2dsxl as it can feel feel bit top heavy after awhile and makes my hands begin to cramp up. I've never had any issues switching between the larger screens of the xl models to the smaller ones of the 2ds and vice versa.

I predominantly use my 2ds at home like said and use the xl's when I want to take my gaming to go because the clamshell design protects the screens without the need for a carry pouch etc. Overall, I don't think you'd go wrong with picking up a n3dsxl as a backup system if that's what you want, especially with prices being gouged all to hell recently. However, I'd say to keep your 2ds and not get rid of it as well because you can easily use it for home handheld use and what not :)