Cervelo P3C or road bike for IM

For IM distance races do I stick with my comfortable TCR carbon road bike (appox 74 degrees) or uprate to a P3C (use 75 degree option)? Just worried on the comfort, well and the cash!

If its comfortable, why change?

Why change? Yes I agree, that’s my problem - I’m looking for an excuse to buy it!

Marathon time - not too good, ran 4:40 last year (1st IM - Austria), hoping to go near 4 hrs this year.

Thanks

Depends on which one fits you better and the course. Not everyone is unilaterally better off on tri geometry. There are those rare exceptions that are better off on road geometry even with aerobars. They are the exception rather than the rule.