I don't know if this will help you but thought it may be a reasonable pointer on Mission subs.
I have had a Mission m7as for around 6 months now and I have been very happy with the product both in terms of sound and performance.
It is little reviewed product (in fact I have not seen a single review) and I opted for it on the basis of:
1. I couldn't justify the £400+ for a REL Q150
2. It was well priced - paid £180 against a £250 RRP
3. I knew it would match the rest of my m7 set-up
4. It was downward firing which I felt would give me more flexibility with positioning
What I like about it most of all is that it gives a well-integrated extension to the base with both music and movies without being obvious. I also like the fact that it doesn't 'pop' into standby when no signal is being received as it stays on once turned on.