What apple product to buy? Using Lightroom, Photoshop, etc.

For the uses you listed, go with any of the mid-to-upper-range iMac or mac Mini models. With the Studio, either one of the two models would be fine. While the tech specs do show differences between the M2 & M3 chips, in real life there is not a huge difference between them; I would not base a buying decision just on the processor.

Regarding RAM, the Adobe apps all require at minimum 16 GB RAM. I have always found it best to not skimp on RAM or disk; and even though Apple Macs do "work differently," that does not mean one can blithely configure a minimal system expecting grand performance. For your uses I would suggest 32GB RAM and 1TB SSD (or more depending on your needs).

If you are a home user an iMac or mac Mini would be fine; just go with a mid-range or higher model. I would not think the Studio would be necessary unless you are doing commercial work or if for other reasons you require that power.

ps. For comparison, I am using a 2019 Intel i9 iMac with 32GB RAM with Photoshop, Lightroom, CaptureOne Pro, Davinci Resolve, Screenflow, iMovie and other apps. It runs them all like a champ. Any of the current M2 or M3 Macs would blow it away.

Also, do sample configurations of both an iMac and a macMini w/Studio Display. When I did that comparison myself a few months ago the mini + Studio display came in cheaper than the iMac! And the Studio Display is 27" not 24".

The Mac Studio uses the M2 Pro or M2 Ultra CPUs, the Mac Mini can use the M2 Pro, while the iMac can only use the M3 entry level CPU.

The M2 Pro and M2 Max will be faster and have better performance than the M3 entry level CPU.

The real question you should be asking, is what is your budget, and what Mac configurations can you then purchase with it.

RAM cannot be upgraded on Macs after purchase, so what you buy is what you will stay with for the entire life of the computer.

For heavy Photoshop work, I would stick to the Mac Mini, with the M2 Pro, and 32GB of RAM regardless.

Yes, Macs make better use of RAM, but its always better to have more and not use it, than to have less and need more and not be able to upgrade it after purchase. Also, for a longer life time, more RAM is always better.

Neither the Mac Mini, nor the Mac Studio have a screen, so you will need to add that into your budget.

The Mac Studio tends to be overkill for most tasks, and the iMac is very much entry level computing.

The Mac Mini, can be figured to offer an in-between level of performance without the large price tag of a Mac Studio but with more performance than the iMac.

Also, consider how many external displays you use. The iMac can only use 1 in addition to its own built in display.

The Mac Mini can run up to 3 displays, and the Mac Studio can run up to 8 in its most powerful configuration with a price tag that is not easy to swallow.

I would not consider the M3 to be an entry-level CPU. The M3Pro & M3Max are only available on the current MacBookPro models (not available on the iMac, mini, Studio or Pro) and the M3 compares quite favorably against the M2Pro.

Here are a couple of reviews to consider:

M2 vs. M3 Buyers Guide (from macrumors)

Nanoreview - M3 vs. M2Pro (pretty comparable, they just edge each other out on different tests)

But it is. Its the lowest available M3 CPU available, a.k.a Entry Level.

I'm not saying its weak or under powered. but it is the most basic CPU available for the newer Macs.

M2 Pro and M2 Max have more cores and will have better performance in most tasks than the regular M3.

Whether that improvement is noticeable is a different question.

The M3 Pro and M3 Max are not part of this discussion, because they are not available on the Mac Mini or Mac Studio yet. Only on the MacBook Pros which apparently are not being considered.