Honestly, a 55" tv is too small to benefit from 4K vs 1080p anyway. You'll benefit from the enhanced contrast and HDR and it may seem sharper, but 4K you just have to be about 3 feet from a 55" tv to really see it. Upscaled 4K is worse than native 4K of course, so on a tv I would say this really isn't going to matter much either way.
On a projector on a big screen you can really start to see the differences. But even the you have to sit very close.
Video: JVC RS4500 135" screen in pure black room no light, htpc nvidia 1080ti.
Audio: Anthem mrx720 running 7.1.4, McIntosh MC-303, MC-152, B&W 802d3 LR, B&W HTM1D3 center, B&W 805d3 surround, B&W 702S2 rear, B&W 706s2 x 4 shelf mounted for atmos, 2 sub arrays both infinite baffle: 4x15 fi audio running on behringer ep4000 + 4x12 fi audio running on 2nd ep4000.