By F1 sim, do you mean you'll be playing F1 2021, or another sim with F1 cars?
If it's just for F1 2021, and others may disagree with me here (so please add input guys!), then the force feedback is a bit rubbish. I really struggled to get my Simucube 1 working properly, or at all. In the end I had to buy an emulator dongle that made the PC think it was a logitech wheel, and even then in game the forces were a bit rubbish (it was nothing, nothing, nothing, nothing, go insane and try to break your arm, then back to nothing, nothing, nothing...etc.).
So if it were me, and this is just for F1 2021 mind, I'd go with the fanatec CSW because it's more mainstream and supported better in less 'hardcore' sims (I hate that phrase). That said, the accuforce has its own force feedback system so that may well work better in F1 2021, I have no experience of it though.
If it's for other sims, R Factor, AMS1/2, Assetto Corsa, etc. then definitely a Simucube 1/Simucube 2/Accuforce/Simagic will be great, and in my opinion better than a Fanatec CSW2.5.
Of course the next option is the Fanatec CSL DD, which has all the benefits of a DD wheel, aside from high torque, but for the price of a CSW 2.5. Definitely worth looking at reviews of it, which from what I've seen have been very positive so far (though I can't remember a negative review of anything by any of the usual sim racing youtubers, so take them with a pinch of salt). Downside is there's a wait for the CSL DD since it's so new.