are terrific value IMHO.
I am shopping for a new one too...
The 182-188c probably has all you want and has a fast enough screen update even for speedy ribbing, even with course up displayed.
That's what I am looking at..
This was discussed
The 2006 and 2010 have both been cut in price to compete with the 182/188 and are great value if you have room for them.
It may also mean that Garmin are bringing out new hi-end plotters but that is pure FUD...
The really cheap handhelds do a great job too as long as you do all your plotting at home on the PC and then stick to the planned route and the "motorway" display..;-)
but IMHO, they are too slow for everything other than reality checks of positioning in slow speeds or still in combination with real paper charts.
may be a good place for specific questions, as they even have a BBS like this one.
the marine section appears pretty silent though..
Hope this helps