We did this some years ago with our son. I have to say it was a useless expense and a horrendous experience which accomplished nothing. If you don't know how this works, a sensor is put into the crotch area - our system was done by me hand-sewing a small pounch into his underwear, and then the sensor was inserted. That part was easy. We just dedicated a couple of pairs of underpants to nighttime sleep. The underwear fit more tightly than the pajama bottoms alone. I don't know if the systems have changed at all since then, but again, this wasn't the problem - it seems to me that the theory remains the same.
However, from there, we were all awakened several times per night by a loud buzzing - every night, we thought first it was the smoke alarm. Then I would rush into my son's bedroom, pull the sensor out of his wet underwear to silence the alarm, and then get him to the bathroom. Remember that the alarm doesn't go off until he's already wet. Then we changed clothes and sheets, etc.
The theory is that the alarm will so annoy the child that he will wake up in subsequent nights. I don't see how this works in a child who is not developmentally ready, whose bladder does not send the "full" signal to the brain so that the brain wakes up. How does the alarm system manage to stimulate the brain this way, since it is after the fact? To this day, we don't even know if the alarm scared him so much that he peed even more, you know?
After a month of torture, the pediatrician agreed it was a pointless experiment, and referred us to a pediatric urologist. This specialist taught us a lot about nighttime bedwetting (called nocturnal enuresis), said he wasn't surprised that the alarm didn't work, and after discussion, recommended a medication that absolutely stopped the problem. Our son simply took a pill before bed, and that was it. I'm not a big proponent of medication when other things will do, believe me. I'm in the nutrition business and have seen firsthand how great supplementing can help. If I had known then what I know now, I would have tried this supplement. However, if it didn't help, I would still absolutely go back to the medication. There were no side effects and the MD told us that there are even kids (particularly boys) who stay on it through and past puberty with no ill effects.
Our son decided to try going off the medication at around age 8 I think. The bedwetting came back after a few weeks. So he went back on the meds and stayed on them till about age 10 or 11, when he decided to try stopping and did fine.
During the years he was on this single pill per night, he was able to go to and host sleepovers, and go away to 4 weeks of overnight camp, and had such marvelous experiences. I wouldn't trade those happy years for anything. If he went to a friend's house, I just sent one pill in an unmarked pill bottle - the pharmacist gave me something with his name on it but not the name of the medication. I made sure the hosting parents gave him his pill before bed - if they were close friends, I told them what it was, but otherwise, I didn't. When he went to camp, the nurses were giving out all kinds of meds to all kinds of kids for all kinds of reasons - the other kids couldn't have cared less and no one knew what the deal was. My son was happy, he slept through the night in dry sheets for years, and everyone was much happier.
If I were you, I would get a second opinion from a pedi urologist before investing in this equipment. Find out how it really works. If they tell you it is "training" the child to wake up out of avoidance, find out how it is really helping their brain development or why sleep interruption is beneficial/preferable. I realize your child is waking up now due to being wet, but really ask how this is going to help develop a neurological connection that isn't working now. Then ask about the medication (sorry I don't remember the name) and ask for the pros and cons of each type of therapy.
Good luck, whatever you decide!