I been using Ringo with my Treo 650, 700p, 700wx and 800w. It worked good with the Treo 650, 700p and 700wx. I only have a few problems that bugs me while using Ringo on the Treo 800w. When you are on a phone call and receive a text message you will hear the music through the earpiece on the phone or on your bluetooth loudly. When you receive a voice call and you click over to answer, the ring tone starts playing multiple times loudly and i have to resort to hanging up to stop it. Also you can not use a ringtone that is stored on your memory card, it will transfer the ringtone to your main memory. The last problem is ringtone volume being low. I just installed Mring last night and so far it does not have the same bugs that i mentioned about Ringo. It seems to be a decent volume. You can store ring tones on your memory card as it advertised. The main thing i do not like is the profile part of the application with it today plugin. Other than that, it seems to be stable and I recommend you to try it if Ringo is not working for you.