You don't get that much tobacco taste with these blends, especially the Rumcake. The tobaccos are high quality and the Jamaican rum used is really good. I prefer the #515 because it has more flavor nuance. Here's my reviews of both:
Rumcake:
The Jamaican rum is richly sweet with a little spice and is the star flavor. You will taste a light honey note from the gold cavendish from time to time, and some vanilla from either a topping or black cavendish or both (I suspect both is the correct answer). I occasionally get a hint of burley, but it's strictly condimental, as is the Virginia, which is slightly grassy when you notice it. May need a slight dry time because it is moist, but drying it will lose you some of the rum, so you'll have to decide how you want to play it. Burns well and slow, but needs to be sipped to avoid some dottle, and the tongue tingle that can arise for the faster puffer.
#515:
This blend took me a little time to figure out how I felt about it. It's not as sweet as I expected, and has a floral essence that may not suit some smokers. There's a light vanilla note that plays well with the spicy rum flavor, which is moderate in strength. I suspect a touch of coumarin or deer tongue is present, too, which would account for the floral notes and vanilla, though black cavendish also accounts for the vanilla. The Virginia is hay-like, grassy, lightly sweet, and as another reviewer suspected, is of the flue cured variety. It may bite if puffed at a fast rate, but it does burn well, even, and leaves no moisture. The room note is sweet and very mildly floral.
Having smoked a bit of it now, I'm reminded just a little of Germain's Plum Cake. Both must use a similar type of dark spice rum. An interesting change of pace smoke for me, though I have found myself wanting to smoke a bowl a day since I started smoking it. I consider this to be a blend one has to work one's way into to enjoy. If you get used to the floral flavor -which isn't very strong - you'll like it. If you don't, well, you probably won't.