The wife and I used to have an Autocom setup on our bikes, using PMR to talk between bikes. When we both swapped bikes I soon realised that there was nowhere to mount the units on either of the bikes.
Bearing that in mind I sold the Autocom units and the PMRs and bought us both a Scala G4. I paid about £270 from some Italian on ebay (recommended from this site).
Initially I had a few teething troubles, but that was down to a combination of the Zumo firmware (we both had Zumos) and the phones. Even during this time, the thing that always worked was the Scala to Scala comms. It was the GPS/phone that kept disconnecting from the units.
Once the devices in question were updated everything started to work beautifully. We've not had any issues since, baring the odd crash of the Zumo. However, I used to get that even with the Autocom since I had to use a combination of hard wire and bluetooth between the Autocom and Zumo to solve the telephone issue. In case you aren't aware, the telephone issue is when the Zumo and Autocom are only connected by cable and the Autocom can't differentiate between "sat nav speech" and "telephone speech", so when using the phone via the Zumo it cuts the volume of the other party by 50% every time you speak, making phone calls almost impossible. The solution was to connect the Zumo to the Autocom by hard wire for music and bluetooth for telephone calls.
One thing to bear in mind though is that if you have the Zumo 500/550 you will get really poor music through bluetooth due to it not supporting A2DP. I soon got fed up with it and traded up to a Zumo 660 (also partly because mine was getting on a bit and needed the screen replacing too). The wife decided to stick with her relatively new Zumo 550 and just used a 3.5mm audio cable between it and the Scala. It does mean she can't control the music using the Scala, but it's no big deal since all the controls are right there in front of her on the Zumo.
I am really please I chose (or rather was forced) down this route. We'd had loads of issues in the past with the Autocom units and the PMR. They worked really well, but only when they felt like it. A friend of mine also had to make the same choice when he changed bike, so he went for the G4 as well. We all did a week tour up round Scotland and the isle of Arran last year and had not a single problem between the 3 of us. The 3 way intercom between all the G4s worked perfectly.
Admittedly the range on the Scala units isn't as good as the PMR with Autocom was, but it's no issue and the range is plenty enough. It gets a bit ropey when separated by buildings and hills, but then so did the PMRs even when we were using the number plate mounted external aerials from Biker's Oracle.
Hope that helps,
Dae.
