West Wind's 18mm Gothic Horror Line is so good that you will feel yourself pressed to try their top notch 28mm line as result! 
Chaos in Carpathia is a great game as well, and the cinematic setting will make you look for a more detailed perspective (28mm) - in this scale, not only the painting and conversion of the miniatures are more enjoyable to do, but I bet you will soon find great joy in making gothic terrain in this scale as well!
You're correct. After a stretch of indecision, I eventually ordered some 28mm models after all. I really liked the Westwind Brotherhood models, the loup garou, etc. Also, the Hovels terrain shown off by Jet in Geektactica was a lot cheaper than Blue Moons 15mm terrain (even if it was probably better sculpted). I might pick up Blue Moon's 15mm models one day, just to have them.
Also, if I had switched to centimeters for 15mm gaming, I would have had a 48cm playing area in order to keep scale.