I have the Travelpilot DXR70, but much prefer the TTG, it is so much better having the full colour display with real maps and also the benefit of speed camera warnings.
I mounted mine to the right of the instrument cluster and it looks OK, it would be nice to try and build it into the ashtray area but the great thing about the TTG is that it can be easily moved between cars.
The Blaupunkt also uses DX discs, I have the 2003 maps and it is very out of date, gets me lost more than getting it right, hence why I went for the TTG.