Been a long time since we stayed BLT TPV, so my memory of it may be off. Space Mountain is absolutely a major part. I didn’t recall much of a castle view, but we didn’t have a high floor.
Ironically, we have booked Standard (Resort) View and had very good views of Space Mountain and fireworks. This experience is why we stopped booking TPV there.
Personally, like the Preferred/Lake view at BLT. It’s also why we like the RIV Preferred View. Love watching lake activity without watching cars/trucks/buses.
For me, LSL having a beautiful lake view and having good activities (lazy river) is why LSL is intriguing. As someone who loves WDW history, Polynesian, CR, and CFW are the originals. We own two. Will not buy CFW (dues), but maybe LSL? (Much depends on what the finished product,
point charts, dues, etc)