I don't fly too much in DCS, usually take pauses of several weeks or months between more regular flying.
With that, I find the F-4 fairly easy, especially as I have decent hours in the Viggen and F-14. Compared to my favourite single-seater, the much more modern F-16, it's easier to remember the steps and workflows for me. Less fiddling with MFDs, remembering what menus things are buried under (although the 16 is much better in this than the 18 IMO).
Landing funnily enough is some of the easiest for me. 200kts or slightly less depending on weight, slight nose up, touchdown, pull chute.
In the F-16 you have to aerobrake, the F-14 just weers of the runway for me and with the Viggen I am guaranteed to blow at least 1 tire per landing.
Everything has a button and buttons that belong together are grouped (mostly) together.
Jester helps tremendously and the less complex nature of the aircraft compared to, say the F-14 (much weaker radar, no pulse doppler, so no contacts dropping due to various conditions) there's less to worry about. Also much less SA, like 0 (no datalink!)
Currently, Jester cannot control the TGP yet and seems to have lost vital skills like speed callouts during dogfights, but I'm sure this stuff will be added down the line.
Since you mentioned the Tomcat though, the radar in the Phantom is pretty bad compared to it. Unless you are at co-altitude or below a target and ~25nm away, you're probably not gonna catch anything with it, maybe a bomber. So engagements are all medium-short range, by the time you pick something up heading to you, you are very close to being in weapons range.
Still figuring out the sparrows, but the sidewinders I like so far. Simple to use.