I need to revise my comment about there being a lot of monitors available between the Phillips and the Apple Studio Monitor. Looking at only curved monitors limits the options significantly. Also, you can evaluate the cost, aesthetic and acoustic implications in your set up far better than I can. I'll also refer to my #1 monitor/TV resource, rtings.com, with their detailed image measurements.
For size and image quality (IQ), you've already commented that you love the image of the Apple iMac and also appreciate the bigger screen size of the 34" Phillips. Logic and Luna are your main applications. So you're in the subset "office setting" for what people generally want in a monitor, which is what the Apple studio monitor is optimized for. So I'm making the assumption that that's what you want.
First, some background, and you already know at least some of this:
You're aware of the three different main panel technologies of OLED, VA and IPS. OLED isn't great because it can't get much brighter than 300 nits and because of its problems with burn-in of static images that are displayed on the same place of the monitor for long periods of time. VA panels have the advantage of better contrast when implemented well. IPS panels have the advantage of a larger viewing angle. Interestingly, Apple uses IPS panels for both MacBooks, where IPS is listed in the specs, and in the Apple Studio Monitor, but its specs don't list that. Apple is very selective about which specs they publish. They publish the ones that are great and often don't mention the ones that aren't.
Brightness is analogous to loudness. In both cases, the perception of each is approximately logarithmic so doubling the brightness would be equivalent to a 3 dB volume increase, noticeable but not huge.
Pixel density (pixels or dots per inch or ppi) is analogous to samples per second. In both cases, there is a level below which you start to notice a degradation of the signal with loss of high frequencies in audio and fine detail on the screen. There's also an analogous difference in both of these between the recording samples/second or ppi where any quantization error can be compounded by processing of the signal and the display format where are you seeing or hearing it directly and the same amount of resolution isn't required. For me, the sweet spot for display is around 160 ppi, which is the resolution of my 28" 4K monitor. On that you have to get really close to see any sort of pixelation, or graininess. The 226 PPI on my MacBook is great, but it's so fine that I really don't like it that much better than my main monitor. On one of my older monitors more than a decade ago I believe the resolution was 72 ppi and that would be unusable for me now.
In office settings, many of the other specs don't matter as much, including contrast, color gamut, frame rate, jitter since you're not playing video games or doing color grading for projection in a cinema setting.
Apple screens are bright (600 nits), great in pixel density (226 ppi as noted above) and with image/color accuracy (the colors are what they're supposed to be, within the limits of the colors that it can show). Using the
rtings.com measurements, the Apple IPS panel isn't great with contrast and its color gamut (the ability to show pure/deep reds, greens, blues) also isn't great but since you're not video editing those attributes probably don't matter much.
The advantages of the Phillips are the curve and with the additional size. Why the image doesn't look as good to you is likely because of the lower brightness (300 nits) and lower sharpness (pixel density of 110 ppi so that you're probably seeing the individual pixels, some 'grain' in the image). As I had previously mentioned, if you brought your iMac back down to your studio those differences would probably be pretty obvious, as well as how important those and any other differences are. Also, you may be able to adjust the contrast & color so it may look better but the lower pixel density and brightness are locked in by the hardware.
For curved monitors that I noticed (not considering any Chinese ones) other 34" curved monitors looked like they have an IQ pretty similar to the Phillips. The two alternatives to the Apple Studio Monitor that rtings mentioned are both 40" curved monitors,
LG and
Dell. Both have 140 ppi sharpness. Both are 5.1K monitors like the Apple but with those pixels spread out over a larger area; the Phillips is only 3.4K. The Dell has a 600 nit peak brightness and better contrast than the Apple while the LG is like the Phillips in brightness & contrast. Both cost > $1K; the Dell is a bit more than the Apple.
Hope that helps.
If anything's not clear or you have other questions please ask.