I've also been looking for a GNII replacement. It's a nice program,
but lacks a few important features -- it doesn't have a bottom to top
thermal average, and support for figuring out how long it will take to
finish a turn area or MAT flight is sketchy. Terrain map with landable
footprint also seems very useful in ridge country.

The main problem I've found is that other programs are not attuned to
US contest rules (or maybe vice versa!) They are designed for casual
cross country, OLC, or contests under European rules.

Task entry is a big issue. We often get tasks on the grid, 10 mintues
before takeoff. We often get tasks in the air, 10 minutes before the
start gate opens. (Let's not get off topic on a discussion of this
fact. Europeans will say, how dangeorous to change tasks in midair.
We'll say, how dangerous to send the whole fleet off into a
thunderstorm just because you were too rigid to change task in the
air. End of discussion.) This means US contest pilots absolutely need
quick, easy, goof-proof task entry. The GNII, designed for US
contests, is good at this. The others I evaluated are not. Even a few
more clicks, or a few more chances to freeze the whole thing by
pushing the wrong button, are a severe downside. I threw away one
program at Mifflin, when it froze my PDA and GPS while trying to enter
a task just before the start. (Yes I pushed the wrong button, but I
was looking out the window a lot, and why do I need to see boxes with
runway details when I'm picking a task?)

The US also has the MAT task, where you pick the turnpoints that end
the flight. Again, this means you have to evaluate lots of different
task options, while in the air, and sometimes while barreling down the
ridge at 100 knots or with traffic around. Simple, "what if" task
modification is vital. This is much harder on most of the programs I
evaluated, though their time estimates are better than GNII once the
task is entered.

As a minor issue, you want the program to handle US configured start
and finish gates, and US turnpoints. That's also present in GNII
(except for safety finish glideslope, but nobody has that yet).

Wind calculation is important issue, and hard to evaluate. The acid
test, for me, is: I've been barreling along the ridge without turning
for 400 miles (MIffin 2007). The ridge is about to make a sharp right
turn. Is the wind strength/direction going to keep me up around the
corner? Or, I'm thermaling, and want to try the ridge. Well, is it 310
at 12, or is it 280 at 8? GNII is about medium on this. In my
experience the SN10 was better, but that's not a PDA program.

I'm hoping the clear-nav will solve all these problems (plus
visibility), though the cost in dollars and watts will be a lot more
than a PDA.

John Cochrane