Share your experience!
Yes, they are aware but officially respond with stuff like "check your router". However, there are lots of people with this problem - just use the search and you'll find out 
As for me - sitting 2 metres from the router gives medium strength connection on the Xperia SP, while two laptops, one tablet two Lumias and few more Nokia/HTCs give full connection. When not in the same room the SP starts dropping connection, while the other devices have either full or next-to-full conection strength. Pity!
Let's hope that 4.3/4.4 would fix this.
I alsmost have the same problem as yours. I don't have much devices connected to my router (only 2 laptops, 2 mobile phones and a PS3 and they are connected only for say 8-12 hours at a given day and that's it).
I just feel that Sony are just ignoring the problems (read: burying their heads in the sand) and is too slow in addressing such & such issues. In my other thread i've pointed out several problems with the SP and NEVER had a single reply from them. That shows the kind of ignorance/arrogant culture they have.