The trouble, as I understand it from my tame radio bloke, with the Garmin 430/530 is that it's all in one box...radio,GPS, etc...if said box goes west you lose a lot/the lot...hence why many Garmin fits have one of each...that's a lot of money in anyone's book.
For this reason I went with the following when I replaced the radios in my Bonanza a year ago.
Garmin GMA 340 audio panel
KLN 90b IFR/App GPS
Kx155 Navcom
Icom slimline second VHF (VFR)
I left in place the original
KR87 ADF
King DME
Century 111 autopilot
HF (this is Australia we still use HF sometimes)
The KLN90b and kx155 were OHC but are effectively brand spanking new...the 340 audio and ICOm were new.
While the 767 I fly for a living has all the EFIS moving map stuff I think it is over kill in a light aircraft and does not give you the systems redundancy I like....in the 767 of course we have multiple ADCs, EFI etc so not an issue...you won't have that in your average light aircraft.
I'm not much impressed with the new all glass cockpits for the same reasons...they are more marketing than substance in my opinion.
In my aircraft I can lose any one system and be unaffected in any way.
The other positive is that the gear I fitted was relatively cheap because every man and his dog is salivating over G530/430s etc. Good OHC KLN90bs and KLN 94s are very cheap and an excellent unit. Use the money you save to fit a good HSI if you think you need it. I never fly ILSs in my Bonanza because nowhere in Australia has them outside capital city airports and I don't go to them...I just fitted a new king CDI with the Kx155.