Thinking about getting some new monitors. Is the difference between IPS and TN a big deal when using Cubase/Nuendo? Thoughts?
Not so much. It’s mostly relevant if you’re doing video/image work, where truthful colour representation is essential.
For a DAW it doesn’t matter much.
IPS screens tend to have much better viewing angles, so when viewing off axis, colours don’t wash out or go metallic so quickly. TN screens tend to have poor vertical viewing angles. IPS screens tend to be well calibrated out of the box these days.
Thus, for touchscreens, where vertical viewing angles tend to be quite off axis, IPS screens are essential. Otherwise, for on axis viewing, your choice.
However, make sure you see a TN screen before buying.
Note that if using a TV as a monitor, very few are IPS, and even if they are, good colour is not guaranteed (looking at LG here). Always view one ‘in the flesh’.
When contemplating getting a 4K TV for a monitor, I put a 4K sized screen shot of Cubase and RX onto a USB drive, just so I could get an idea of what it looked like. At typical computer viewing distances, a 48" 4K flatscreen is OK, but go to a 55" and a curved one is less likely to go off-colour at the sides. Just know that the colour will be turned up to ‘show off’ mode, but you should be able to tell if the colour saturation and viewing angles are handled well.
Note that with TVs, you WILL have to change the colour settings to something less garish than the standard ones, usually starting with Movie mode and doing the White Balance adjustment. If possible read a review of a prospective one on a proper TV review site, where they calibrate the TV and do the full colour tests, and they may show the settings required to be able to do those properly. Those settings are what you will find are the best for use as a monitor, but also for when you kick back and watch a movie.
You may have to search the internet specifically for explicit settings for the model, and try them out. It was in a review of an LG 2014 IPS model that they indicated that colour couldn’t be corrected, thus scrubbing that model off my list.