I'm going to go against the opinionated recommendation of the Internet and obtain a PS4 Pro. However, I intend to do this by trading in my current PS4 and a couple of its games (one I don't play and the other I decided to buy the digital version because I like not having to swap discs), the PS3 that I'm not playing anymore and all its games that I have that I no longer play because I'm always playing my PS4. This (I've already talked with the clerk at Gamestop with my list of trades) will reduce my purchase to about $236 for a PS4 Pro, and there is the possibility Gamestop may run a promo for additional value when trading in a used PS4 for a PS4 Pro.
I don't have a 4k TV, and I really don't care about that. I'm perfectly fine with 1080p gaming, which, it turns out, I've actually not even been really getting that. I've really been getting 900p gaming from the current generation. From what I can tell, the PS4 (with the caveat that game developers support it in their games) bring to me ACTUAL 1080p gaming on my 1080p TV at 60fps, rather than 30fps. It will allow increases (again, assuming the game developers support it in their games) to environmental details, number of rendered objects on screen, character model details, controller responsiveness, visual effects, and frame rate stability (i.e. I get 1080p at 60fps and it STAYS AT 60fps!). These are fairly significant improvements to the gaming experience, in my opinion, that are independent of 4k resolution, and, as many have pointed out, the jump from 1080p to 4k is less a differential than has been the jump from 480p or even 720p to 1080p. I do not believe my TV can do HDR, so I will be missing out on that feature. However, I still feel that in the features I would get, there is value in making the trade-up to the PS4 Pro.
My feeling why 1080p to 4k feels like less an improvement is because the difference in angular separation, for the same viewing distance, of the pixel between 1080p versus 4k is less than the case for 480p/720p versus 1080p. Part of this, I think, stems from the fact that we, nowadays, make the mistake of distinguishing resolution by numerical pixel count (which is an artifice of multiple factors) instead of by its original definition, from astronomy, which is the smallest angular separation that can exist between two points and still allow those two points to be visually resolved as being two distinct points. (This is the same misunderstanding that plagued the whole stink around Apple's whole Retina Display; the specific numerical pixel resolutions are the result of requiring pixels have an angular separation of no more than roughly 1 arcminute at a range of view distances of 3--5 feet for displays in a range of sizes from 13" to 27".) Also, and this may have more to do with it, perceptual increases tend to work on a logarithmic scale as opposed to a linear scale, so twice as much numerical size does not translate to twice as much perceptual size. For example, sound is measured in decibels, which is 10 times the base-10 logarithm of the power in watts divided by 10^(-12) watts. A sound that has twice the power only has an additive 10*log10(2) increase in its perceptual loudness. This is a substantial increase for extremely quiet sounds, but for loud sounds, it's marginal at best. To actually affect a proper doubling in the loudness, as measured in decibels, you would actually be squaring the power, not simply multiplying by 2.
Regardless, this is beside the point. My main point is that 4k resolution is simply one feature and not even the most important enhancement feature, in my opinion, that the more powerful hardware can afford. The many other effects that can be afforded by the hardware increase are more important, in my opinion, to increasing the gaming experience than simply having the exact same image that I have now but with more pixels (and HDR). But I will admit one thing, if I did not have trades of sufficient value that I could make, then, yes, I probably would not be buying the system; I would likely just stick with my PS4 until the next-next generation. If I didn't have a PS4 already, I probably would just wait until the XBox One Scorpio before making a final decision. But, the case is that I do have sufficient trade-in value, and I do see significant enhancements to the gaming experience, that I feel are more important than 4k resolution, being possible on the PS4 Pro. Therefore, I feel comfortable and within good reason to make the trade for the upgrade. One could make the argument "why not just wait until the XBox Scorpio and make the same trade?". The answer is because I am already invested in games on the PS4, and I don't have the money to spare repurchasing all my games for XBox Scorpio plus having to buy a new console, even with trade-in value.