I would tend to agree with those who think the GTN650 has a display that is too small as a stand alone unit ( unless you are really pushed for space ) and should be considered as a control head for something like the G500 or as box 2 to a GTN750.
If the STC was developed with a grant, why is it not free to all?
However if it is the one I am thinking of, it was not expensive anyway. @Wigglyamp can drop in with any relevant details.
IMHO, the GTN650 is really a “keypad” for something bigger – unless you are really desperate (or actually fly with a tablet app, and use the IFR GPS for regulatory compliance only or for driving an autopilot). Same for the GNS430 or GNS430W. All these have a near-useless moving map. In IFR one needs to have a reasonable view of the route ahead and how it lies for maybe 200-300nm.
For serious IFR in the Eurocontrol system, one needs something like a GNS530, GNS530W, GTN750 or the IFD540. Then one can use the smaller box as a text-only “FMS”.
I have been looking at all this stuff for ages and always come back to my ancient KLN94+KMD550 being more functional than a single GTN650 or a single-anything would be. Even with a single GTN750, every time you play with anything, you lose the map display.
Finally, IMHO nobody should spend money today (if flying IFR) on a non-W box. Not at the rate at which e.g. France is removing ILS approaches and replacing them with LPV ones.
I have deleted the completely pointlessly “personal” and non-informative posts further back. I really dislike having to do that, not least because I post here also, but this is not one of the UK or German forums which are either run for advertising or essentially unmoderated and where people are constantly biting bits off each other!
I have owned a GNS530W and a GTN650. Some of the 650’s improvements are small, and some take a bit of getting used to, but all in all the 650 is in a different world. The screen is perfectly usable, but if you need bigger you can use the 650 to feed an MFD – or the poor farmer’s alternative, an iPad running Garmin Pilot. The latter, incidentally, offers a level of redundancy: switching automatically to its internal battery and/or GPS chip whenever the panel mounted stuff goes t/u.
I’m surely in the minority here, but for goodness sake don’t squander cash and panel space on a 20 year old electronic fossil – any more than you would go out and buy an Intel Pentium PC running Windows 98.
I am with Jacko and would much prefer a single GTN650. The screen issue is overstated and compared to a 430 it is far better due to resolution.
I had dual 650s in my Mirage and they were great. Ok of course a 650 and 750 would be better if you don’t have an MFD but I really think people make to much of this. If you don’t like the 650 why install of 430 as the screen less useful?
The 650/750 with iPad and Garmin Pilot is great – another aircraft I fly has that combination. However, we’re starting to compare apples and oranges. The OP indicated he had the opportunity of a used 530W, not a full 650/750 suite. 
Ok, guys…
Thanks for the input…..
now I am as wise as before – electronic fossil or much better to use compared to the new stuff.
Once more, the GTN750 would be the best out of two worlds, but as mentioned, that´s beyond limits
I like my GNS430 a lot, my point is: Does spending a considerable amount of money on a GNS530 makes sense, if I plan to use the aircraft for at least another 10 – 15 years?
Best regards
Frank
You will not regret having two things that the 530W gives you.
Screen size and WAAS
As was said earlier, in this day and age you wouldn’t want to install anything that’s not LPV capable
Buy it if it fits your budget.
You might as well keep the GNS430. If the budget is tight you can have it upgrade later to the W spec.
Frank, are you keeping a 430 and asking if a 530 (not a 530W) is worth getting? How much is a 530 today?
This stuff will be perfectly fine for Eurocontrol IFR.
Except it won’t do LPV. Whether LPV is worth spending money on depends on where you fly. For example, I am UK based and there are almost no LPVs in the UK, and when I fly abroad I need customs/immigration and most of those have an ILS, or some other IAP which I can fly with a GPS and I don’t fly to those places in really crappy wx (and my alternates nearly always have an ILS), so I am not rushing to spend money on LPV capability.
Peter wrote:
rank, are you keeping a 430 and asking if a 530 (not a 530W) is worth getting?
The first post said he was considering a 530W
Peter,
I think that we are likely to be surprised how rapidly LPV takes over from ILS, even in the UK.
