As a really good quality BT intercom unit where the Satellite radio and the GPS can be heard crystal clear...
The quality of the bike audio system's BT implementation is poor. As a result, you may or may not be satisfied with the quality of music from any audio source with any headset. So be aware of that. There are endless threads on BT headsets on the K1600 forum
, but I think the Sena units seem to be the preferred ones at this time. This changes of course as new models/software updates come out.
The other factor with the headset is which of a seemingly infinite variety of pairing options you choose with GPS/phone/which phone.
I use a Cardo G9 paired to my GPS (Nav V) and the bike's audio system. The GPS is paired to my iPhone 5S and handles all phone calls. This works pretty well. The volume level is marginal using the helmet speakers with ear plugs, but I would call it satisfactory most of the time.
The newer G9X cradle has a jack so you can plug in earbuds rather than use the helmet speaker, if you want to go in that direction.
Does Nav V makes a huge difference than IV ? I mean does it worth the expense if the IV still working as it supposed to ?
The Nav V is faster, has an easier-to-read screen, and has some very nifty features...the main one for me is the ability to use your smart phone's internet connection to call up weather information, including a weather radar display. To me, this feature alone was worth the cost of upgrading as it can quite literally be a life-saver.
As far as basic navigation goes, the IV works fine. The readability of the V is better for most riders, although it still can wash out with certain sun conditions. Different people report different results, and my theory is that the taller you sit in the saddle, the better the readability is. Some will tell you that the readability of the V is not enough better for them to warrant the upgrade cost.
If the audio system is really important to you, be aware that the Nav V induces lots more noise into the audio system than the Nav IV does. So again, that may or may not be a big deal to you. I notice it, but it's not a big deal for me. YMMV
Also, be aware that there is a different instrument panel shroud for the Nav V, to accommodate the larger display. It's a $40 or so part as I recall, and is an easy swap. But that will add a few more $ to the upgrade cost.
Which brand/model considered the best tires for GTL ? Quiet and good gripping, long lasting on dry roads.. I ride in California so 99.9% of my rides are on bone dry roads!
Now you've done it.
You will get every answer imaginable for this. I have had very good luck with Pilot Road 4 and Pirelli Angel GT. In both cases, make sure you get the versions rated for the 1600...a stiffer sidewall which better handles the bike's weight. The stiffer-sidewall version for the PR4 is the "GT", while the stiffer version for the Pirelli GT is an "A". (Just to keep it confusing.)
Again, you will find endless threads on all of these issues on the K1600 forum