Raspberry can be a finicky wine. It does not do well if left on the gross lees to long, and the seeds can nearly ruin it if not removed completely after fermentation. With that said, I have had both dry, semi sweet, and desert sweet raspberry wine. I found all to be delightful in their proper context. The appreciation of any particular style of wine Is subjective, Like a beautiful woman. However, beauty is in the eye of the beholder.
I would ferment to dryness. sample just before bottling, If I like the way it tasted and feels on the pallet, I would work under the assumption that it will get better with time and bottle it as is. If I was not satisfied with the current results. I would sweeten to where it was satisfactory then bottle. Again under the assumption that time would bond the fruit and bring it's sweetness forward.