I have both those scents and they're great. Yes, that's good taste. You smell good whatever the season. If being a two scent guy works for you- great. Welcome to Basenotes.
Creed is kind of the King Kong of niche. Guerlain is a little harder to pin. Scent is I guess their primary source of income, but I believe they also have a large line of cosmetic products. They're not as big as Chanel or Dior, etc, but opinions seem mixed on whether to classify them niche or not. They probably don't exactly qualify for designer either. Kind of in the middle.
I too probably lean toward preferring L'Instant EdT. But I often layer Edt with EdP. Like 'em both.
BTW, there is a fantastic L'Instant shower gel and the VIW bar soap is fantastic as well. If you're going to stick with these two, the soaps could really enhance the experience
If you're looking to expand your fragrance wardrobe, you're in the right place.