It's not even a fair comparison!
GO is above the 2 in terms of presence and finishes. The price also reflects this.
The GO is probably the best as a horology piece. If you're looking for a family heirloom and something that can make people say wow, this is it! If one had to choose only one German time piece, this has to be in the short list! Nuff said!
However if you're looking for an everyday, from beach to boardroom sort of watch, I'd lean more to the IWC Ingenieur Vintage. The brown sunburst dial with the red tip sweeping second hand is something I can imagine you'd wear for life. Simple and robust, well-built and crafted simply and beautifully. It has all the German accent design as well. Tried it once with my watch buddy and it still stuck in my head as one of the nicest and simplest piece out there. It's on my hunting list as well (if I have the means)... this is a shot I took of his wrist, which reflects more of the actual colour as compared to the Watch Gallery photo...

Not a fan of Speedy. However, with the countless reiterations of this model, I think your choice does stands out a bit from the rest. It's too much on the safe side, IMHO.
I'd strongly suggest to take a chance with the first 2 choice I mentioned above. Anyway, remember that wrist shot once you've decided! Good luck!