The Sonic Touch will be Sonic Innovations first receiver in the canal open fit BTE. It is slightly smaller than the Dot. The dot was, up until now, the smallest RIC BTE on the market.
As stated earlier, though, the Dot 10 vs the Dot 30 will be a little different, as you are comparing a basic to a top of the line model, although the microchip is the same and using the same WARP processor, the directionality functions as well as the ability to fine tune the instruments, particularly using the environmental optimizer is not available in the Dot 10 or 20.
As for the Sonic Touch, it is based on their Velocity model, which is a great sounding hearing aid, provided that there is no feedback. I have not tried the Touch yet, but based on the previous issues with feedback on the Velocity instruments, make sure that if you get them, that they do speech mapping or real ear measurements to prove to you that it is providing the necessary correction in the high pitches and that they are not rolling off the highs to prevent feedback.
This is where the Dot may be a little better, as their feedback cancellation, in my opinion based on previous experience works better.
The Dots do not provide any telecoil or bluetooth options and I believe that this is the same with the Sonic Touch.
Please be aware that Beltone also has a model called Touch, which should not be confused, as the Beltone/Resound models are using the same technology as they are joined as a company.
In the end, go with what works best. If the basic Dot 10 works well, stick with it. Same for the Touch 6 or 12.