I use ambient music for my games and I have since the 80's, though in the 80's it was more just regular music being played in the background. When I started using ambient soundscapes in the 90's my players remarked it added a deeper feeling to the game, especially the more horror oriented scenarios.
Do I use Syrinscape? No.
Why?
It is way to expensive. I think they charge to much for small add ons that only add a few sound tidbits at best.
I say this because there are loads of free alternatives along with loads of free sound bytes all throughout the internet.
For example
Table Top Audio. It has quite a few great ambient sound loops and you can download each of the tracks for your own use.
I combine that with
Jungle palette which is a free soundboard for pod casting that works amazingly great for my games. It recognizes various audio formats and has individual loop and volume functions for each sound byte. You can have an unlimited number of soundboards that are easily accessible. Trust me on this, this little piece of "free" software is awesome. I have also incorporated various other sound bytes from games and movies like mortal kombat (when my players are rolling horrible "that was pathetic" or "It's official, you suck" is hilarious) or movies like the Princess Bride and the Firefly TV show. Mostly it adds some comedy to the table or a more freaky atmosphere for horror scenes.
TBH something like Jingle Palette is what Realm Works needs to integrate instead of another paid add on service like Syrinscape. It would be great to have a simple sound board that supported various formats with the loop and volume functions like Jingle palette does. I mean why do they want to keep adding things that will cost us more money overtime, especially subscription services?
I think they should start adding some new really cool "free" features like the soundboard, PC summaries (player ed) that the GM and other players can see (where they can also post character portraits), and most importantly the calendar function (and I along with my players have come to realize how much this is really needed). I believe these features along with a few others would really get Realm Works noticed by a lot more people.
Please note that I am and always have been a calendar advocate since I first purchased RM over a year ago!