I made a same decision and chose the Ideal Vogue. I haven't regretted it yet, and the 10-year warranty provides significant piece of mind.
Every installer has his favorites, but I have yet to encounter someone who has not been impressed with a Vogue installation. Masood describes it as "absolutely up there with the greatest of the premium items."
That is not to suggest that the Vaillant isn't a first-rate product; it is.