Canon R5 with EF lenses + adaptor - any AF delay?


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I am looking at the Canon R5 with my existing EF Canon lenses + adapter. I may not want to sell all my EF lenses and buy the new RF ones. If you have the camera and you are using it with the adapter and EF lenses, is there any difference compared to the RF lenses... Any AF delay or drawback? I get it. Canon wants us to buy the new RF lens lineup but I am wondering whether I can use my old lenses?
Yes, you can use them and that's probably what most people will be doing.

You'll have to see how each lens you have performs with AF, but the difference will most likely be barely noticeable for most people.
That's basically just you and I, lol.

BTW, OP - if it's not clear, RF lenses will no doubt perform better, but if you're using modern EF glass, I doubt you will notice a difference with most of them. I used to be more cautious in recommending people to make sure before committing to a system, but realized most are using pretty newer glass anyway.
Seem to be working perfectly with with all Canon EF Lens, at as least as fast as they are on the 5D4.

tested 11-24L, 16-35L III, 35L, 24-70LII, 85L 1.4, 70-200L IS 2.8( all versions), 100-400LII, 200L 2, 200-400L. 400L2.8 III

The new RF 50mm and 85 mm are totally different so cannot be compared with the EF mount equivalent. All the above one that I have are latest version, most with the new anti-haze/glare coating, is basically the same.
Further more with the ND adaptor and CPL adaptor is great for travling and video use.
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They work about as well as and occasionally better than they did on my 5DIV.

So far I’ve tested: Canon 70-200/2.8 II, 24-70/2.8 II, 100-400L II, 50/1.8 STM

Also: Sigma 24-105 ART, 120-300/2.8 SPORT, TC1401 and TC2001

All have worked flawlessly with my R5.