We used prenatal peek and it was great. My OB does his own also, so we had 2. My OB did say to be careful where you go. He told me u/s isn't risk free. A study done recently said that an u/s gives the same loud sound equivalent in decibel levels to a subway train pulling in to a station.
You also don't want them to focus too long on one area. And the higher the resolution, the louder the u/s is for the baby.He said just like standing in front of a bass speaker, the baby can potentially feel the sound waves.
Try Miracle View!! They make you feel really comfortable and it's SO fun to see your baby-to-be