I ended up getting both.
RT's early versions had bugs where some items would not read or write correctly to my R30. Some things like the Digital settings such as NAC would be absent after a read. Things like the RF Gain would be set to minimum when I wrote back to the R30.
Then in RT's config screen where all the settings are, several settings were simply missing from the menus and some of the ones listed in the menus just would not read the value stored in the radio when you read the radio in RT's software.
Writes would also not write all the values you set in the software.
One that I don't think was fixed is the time offset used for setting the clock with the built in GPS. Mine always read a value far away from what was stored in the radio. I don't think they ever fixed that even though I reported it.
In RT's credit, they have fixed many of the bugs found over the time the R30 version has been available. Users like us send them bug reports and they usually do fix them. Sometimes they send you an email back saying the bug has been fixed but usually they say nothing. You just need to get used to checking for updates on your own with the built in updater.
RT's software is also kind of slow to open and then it's noticeably slower than Icom CS-R30. It's still very usable though.
RT's software offers the ability to bulk edit a group of memory channels that you can select using standard windows control keys.
It's also a bit friendly for importing and exporting the channel data for use by other programs.
There is a way to get an export from Icom's CS-R30 to import into RT's software and I think the other way around. I think this takes a bit of tinkering though to get it to work right.
For Icom's CS-R30, it's pretty rock solid and is much faster in all aspects than RT's software.
Icom's software also includes every possible setting that can be changed in the radio.
I think the biggest con for Icom's software is the lack of being able to do bulk edits on your memory channels. You must do them one channel at a time which can be a pain if you need to edit a lot. This is where I'll use RT's software to make my edits and then import it all into Icom's software or write it to the radio and then use Icom's software to correct any mistakes found from using RT's software.
If you can swing it, I'd get both.
And by all means, if you find a bug in RT's software, send them a bug report and they will usually fix it pretty darn quick.
If you ever get an Icom R8600, a lot of the data from that radio will import or export from RT's version for use by RT's version for the 8600.
The 8600 data can also be used to import into the R30 version of RT's software. Some edits are needed but it sure makes it easier than doing most of it by hand.
Another nice feature is RT's software does have a Radio Reference import feature for both the R30 and R8600. I don't think it will get everything like maybe trunked systems are omitted but it does good for all conventional systems. I don't recall if it tries to import DMR systems though. If it does, it would probably default the receive mode to one of the FM modes being as the Icom's don't do DMR.
This is all I can remember. I'm sure I've left some things out so maybe others will chime in with their experiences or correction to what I said!
One other thing, make sure you get Icom's latest version of their CD-R30 software and also make sure your R30 has the newest available Firmware version which I think it 1.10 for the US and Overseas version.
Have fun with the R30! They are very nice radios.