A better question would be which is better, LY F or CW on BA. This one isn't even close. You're comparing a fully lie-flat bed (BA F) to angled lie-flat (LY C). Unrestricted aisle access (BA F) to a 2-3-2 layout, or 2-2- upper-deck layout on 744 (LY C). A new product (BA F) to a dated one (LY C).
As for your meal, BA does offer a very good KSML in F. By all means, go for the vegetarian; just pointing out that if you didn't want the KSML because it wouldn't be good, well, it is