Nagagami is on the Garmin Inland Lakes chip. (Although you can only run these maps on a Garmin unit)
http://www8.garmin.com/cartography/inland/canada_lists/Ontario.pdf
Improved clinch for mono and flouro
Uni-Uni for any type of braid > leader knot in which I don't use a barrel swivel.
Palomar for straight Braid to swivel/snap.
Nanofil knot (or double Palomar as I like to call it) for Nanofil.
Leader to tippet (flyfishing) double surgeons.
You have to switch cards.. Some units have dual card readers, in which case you run two at the same time. No big deal swapping cards though, takes about 3 seconds.
Gold will cover all the great lakes, Gbay, trent/severn etc. It won't have inland lakes. You'll need Hotmaps for that. I run both in my 898 (Gold+ and Hotmaps)
Talked to a buddy who makes a living with his camera. I asked him the same question, (Sigma vs Canon).. He let me know that the Sigma is extremely slow to focus during action shots... Stills, not a problem... I think I'll be getting the Canon.