I'm really enjoying it, and think the graphics upgrade is cool, but it does seem odd to not add to the game to fill in some of the gaps, or improve the driving, or clothing poly count. I also thought it was a missed opportunity to not include the clothing and hair from Saints Row 4. I'm glad they did it, but....seems like it was a bit minimal effort.
Having said that I just recently reinstalled Saints Row 2, and I have to admit, that game accept for graphics is far superior to the games that followed. The driving felt more realistic, the world was more fleshed out, and everything just felt more advanced. Hard to see how that wouldn't have been more of a priority. If lighting and texture was going to be the only focus, Saints Row 2 would have been a perfect candadate for an update. Even now it's an impressive game.