I have heard the Futura and the Strads, but, in completely different systems and rooms so I cannot make any sort of comparison. The room/system with the Strad that I am most familiar with is an all out assault on top quality sound. The Strads sound VERY good. They have a beautiful, and natural tonal balance. They worked well with a 30 watt output transformerless tube amp (custom built, one off design). The Futura I heard was in a room that was too small for the speaker, so I really don't know how well it can perform.
A US Sumiko representative has said that the large baffle design of the Strad actually makes it sound very good in small rooms; it can be placed fairly close to the side walls without a major problem. Aside from decorating/space utilization concerns, the Stad should not necessarily be ruled out of use in a small rooms.