Both systems have their strengths and weaknesses.
- It used to be that TT was more useful in Europe and Garmin in NA. Not sure that applies anymore.
- Both Garmin and TT sell MC specific units. ie. Waterproof and vibration proof. lockable, etc.
- Both have units that you can download routes to but not all models are capable of doing this.
- In my hands, the TT I use refreshes/calculates quicker than Garmin but, I stress, that is my experience only with the units I use. TT920 and Zumo 550 & 765
I've never had my hands on a Tom-Tom - but I researched them when I went for my Garmin Zumo 590. I've previously owned the Zumo 550 and 660, and got to know them extremely well. So much so that the reviews that I have read seem to merely scratch the surface of their abilities, rather than giving them a proper workout. The same has to be said for the manuals. They are Ok for describing what they do at a basic level, but rubbish at giving you the detail that you really need to know. They also frequently get things wrong.
If ddrod has the time and knows the TomTom quite well, maybe we could put together a decent comparison between the two devices which might be more helpful. I fully agree with him that it helps to know what it is that you want the satnav to do - but it also helps to know stuff that you don't already know about. There is a lot of mis-information out there to be wary of.
So - to address some specific points.
I've used the various Garmins over here in the Uk with no issues whatsoever. I've always purchased the lifetime map options and these are updated every 3 months or so. They are pretty good - although there are some speed limits that are out of date - but not many.
I never used the lockable feature of the 550 cradle. Too much hassle. I just clip it out of the cradle and either take it with me or stow it with my helmet.
The 550, 660 and 590 / 595 will all connect to a computer and you can transfer routes in and out and access the logfiles which record in great detail the date, time, position, speed and elevation of your particular journey. I use this a lot - the logs are standard GPX files and will import into a whole range of mapping software. I use MemoryMaps for which I have licences for the UK ordnance survey maps, and the accuracy is very impressive.
Like Huey, I like paper maps. But I like the satnav too.
The newer Garmins are very fast - although I don't know how these compare to the TomTom. The 550 was always slow, and the 660 was a big improvement. The 590/595 is a big leap forward.
If ddrod is up for a long distance, side by side comparison, I'll set the ball rolling for the 590. (The 595 has some additional features but is very similar).
I also have a motorcycle press review of the 410 TomTom against the Zumo 595, to which I can refer. But it is rather superficial and for the 590 it isn't entirely accurate.
For me, the 595 is excellent - although it drove me mad when I first switched from the 660.
I use it (sometimes) with MP3 files, which play to both rider and pillion in stereo via my autocom (wired).
It connects to my phone by Bluetooth, and picks up the address book, call log and such like. Both rider and pillion can talk / hear.
Screen is excellent contrary to some reports - probably because out of the cradle, the brightness dims to 40% to save battery.
Dead easy to switch to the car which has its own cradle.
I'll come back in a couple of days with a list.