Tubulars for racing??

There's a few things to consider:

1. Generally speaking they'll roll better than clinchers. While there are some lab tests that find certain clinchers have a lower RR than tubs, on average I think they still come out a bit better.
2. Less complex rim construction/reinforcement usually makes for a lighter wheel.
3. Tubular rims do make carbon wheels a bit more practical and less fragile. Because the tube isn't next to the braking surface, you're unlikely to get heat-induced blowouts. That also means you can use a latex inner tube with a carbon rim. In addition the shape of the rim is also a bit more robust and less likely to get damaged.
4. Provided you've glued it on right, you can ride a tubular flat. That's only really relevant if you've a car behind you with the prospect of a spare wheel.
5. Fitting them is a bit of a faff. You need to stretch them on the rim first, leave them 24 hours and then glue them and then leave another 24 hours usually.
6. Repairing punctures is also a faff. You've the choice of new tyre (expensive), whacking in sealant (messy, unreliable and ultimately ruins the tyre), or opening them up and patching the tube yourself (time consuming).

I used to race on tubulars but stopped bothering with them now that I don't do many open races or stage races when I'd usually have a car behind me. I only use tubs now for TTs.