Well, I own an R3 too -- the black frame with the white top tube. Is that the one you have? I think that is the paint job circa 2015 - 2016. I also have an old Litespeed Tuscany in titanium. At the time Litespeed was still owned by the Lynskey family; my bike has David Lynskey's signature on the chainstay (it's a sticker but that's the way it was done back then). The R3 has Ultegra Di2; the Litespeed has last generation 105. Both are 61cm frames. Both bikes are fun to ride and I'm glad to own each of them.

The Litespeed is silent on the road, noticeably heavier, and most people will tell you that Ti is so much smoother than CF, but to be honest I can't really tell too much of a difference in road buzz in between the two. It could be that I'm running 23s (higher pressure) on the Tuscany and 25s (lower pressure) on the R3. I do, however, feel a difference in the power transfer. The Litespeed takes a little bit more effort to get up to speed but it tends to stay there with less effort. During a full pedal stroke I feel that my legs are fully engaged throughout the rotation. It's easier to keep the bike at a steady state through the stroke. Contrast that with the R3: when you step down on the pedal it goes. I can tell that the bike lurches forward on each power band in the stroke. The bike rewards me when I pedal in a lower cadence and focus on a smooth rotation but it may be related to the fact that I have 175 cranks on the R3 and 172.5 on the Tuscany. It's easier to pedal squares on the R3. The Litespeed is more solid, the Cervelo is more playful.

Generally I'll ride the Litespeed during spring and fall and mostly ride the R3 during the summer. I'm on the Litespeed during the spring when I'm less in shape because it is a full compact crank with 11-32 in the back so I'm able to ease into the rolling hills around here. I end up putting about twice as many miles on the R3 than the Tuscany throughout the year.

If you forced me to pick between the two, I'd give the nod to the R3. If I ever crash the R3 and break the frame I don't think I would replace it and would be happy to have my Litespeed as my "forever bike." That's actually one of the selling points I used to convince my wife to let me get the bike 21 years ago. "...but honey it will be the last bike I'll ever have to buy. It's made of titanium! It will outlast me!"

My advice is that I'd doubt you'll regret getting the Lynskey. Having two bikes that you love to ride isn't a bad thing.