Don't be confused by the two designations Lexus uses for the upscale sport versions of the RC. The F Sport is the tamer 3.5 liter 306 hp one. The F is the even more upscale screamer V8 that has 400+ horses and the price to match....about $30k more.
Really nothing you need to know before purchasing if you have already done your research. But, take your trade in to CarMax first and get their price. It will help in negotiating the value at the new car dealer.
I love the sophistication of the standard RC350 F-Sport but it lacked performance to match it's looks. No one wants their 60k sport coupe to get blown away by a souped up Golf R-type great car that it is, so I turned to the aftermarket and with a growing owner base performance options are out there now and for less than 3 grand I have an RC350 F-Sport faster than its big brother the RF-f. It's still quite and smooth riding when I want it be but a real beast when I let it loose. I love driving this car just for the sake of driving it...even more than my classic 911. Strong recommendation