I spent wayy too long reading posts about this before buying my N3DSXL and in the end ordered two of the refurbished units direct from Nintendo (a red and a galaxy version). They both ended up having dual TN screens but I am keeping the red one because it is way better calibrated colors than the galaxy, which has the dreaded yellow tint on all white backgrounds and and generally just looks more accurate.
The viewing angles don't bother me like I thought they would and I am overall happy with my purchase. At the end of the day, it is a total crapshoot and you could get a very well calibrated TN and a really yucky IPS, the point is that Nintendo really cheaped out on their 3DS screens and thankfully didn't repeat that mistake (for the most part) with the Switch.
The viewing angles don't bother me like I thought they would and I am overall happy with my purchase. At the end of the day, it is a total crapshoot and you could get a very well calibrated TN and a really yucky IPS, the point is that Nintendo really cheaped out on their 3DS screens and thankfully didn't repeat that mistake (for the most part) with the Switch.