Please be advised that the initial cost of any Garmin product, and I would imagine the TomTom is the same is only the beginning. You get one free update within about 6 months of purchase, then after a couple of years you'll start getting anoying messages saying the maps are out of date and to go to their website. The cost of the update is $100.00! That is something I didn't anticipate. I like the product, but I think Garmin is a bit greedy here.
I haven't done the Bizer upload but that's only because I know the lake pretty well and I operate during daylight hours only.