Regarding the transponder upgrade to ES, that really puts you
in a decision situation for how to proceed.

2 things:  One, as you noted, you'd need to upgrade to the
    GTX330 ES and since you have a 327 you'll have to do
    some gadget shuffling to get that to happen.

The other thing is, do you fly at class A airspace type altitudes?
    If you do, you're going to have to have a 1090ES type system
    anyway.  If not (as I do not), you don't really have that concern.

In the case of not flying that high, I really think the simple solution
for most people is to go with a UAT, not get a 1090ES system.
You get WX, traffic, and you'll be sharing traffic directly with
all of the other small planes that use UAT's on 978Mhz.  With
a dual band system you're even better off.  But, at least at that
point you'll even show as traffic to other people's systems who
may have receive only....and that will help them avoid you.

Otherwise, you'll be broadcasting 1090ES and it'll only be
picked up directly by people who have a 1090 reciever, and you'll
have to relay it all to ground stations and back up to the 978mhz
UAT folks.

Personally, I think it stinks that they did the altitude cap on the
978mhz stuff.  If it weren't for that, there would be really NO REASON
why any light plane would want to go 1090ES, because of the
WX/Traffic benefit and better bandwidth that the 978mhz systems
use.

With the Cheltons, too, getting a NavWorX system for around
$2500 total, gives you WX/Traffic and it's a pretty simple install.
If you did 1090ES for OUT, that's fine for OUT compliance, but
you're still going to need the UAT for ADS-B in, and most likely
you'd buy the same box. (Although they do offer a receive only
but I wouldn't recommend going that route).

You just quickly come to a point where the altitude you fly will
be the big determining factor.  You MUST go 1090ES to fly
high....but that doesn't fix all of your "needs".

I'm sure there may be systems that you could integrate down
the road that are dual band, but you'll spend even more money.
That would be the only reason I'd delay the purchase at all.
I've already been flying with ADS-B permanently in my plane
since 2009.  I test flew it in 2008.  If I'd have been on the
skeptical "Wait and see", or "wait for the final ruling" bandwagon,
I'd have missed out on 4 years of traffic avoidance.

Whatever the case, the Chelton can handle ADS-B or active traffic.
To me, the bigger issue is dropping the WSI WX.  You can
absolutely do that, but, keep in mind that FIS-B Wx coverage
is only guaranteed at a certain AGL altitude.  If you are always
flying high, maybe no issue, but for me, I want to have that WX
showing up on the screen even while pre-flight....let alone when I'm
at 2500' zig-zagging under the summer buildups avoiding IMC
and the storm cells totally.  If you fly like that, you may not always
have WX coverage at low altitudes.  That's where WSI really
shines. 

As you can see, the issues are many, and the right choice
for one person is not at all the right choice for all.  You really
have to add your MISSION parameters to the question when
you get on this topic, because that can make all the difference.

Tim

On 8/13/2013 11:01 AM, Douglas Brunner wrote: