You can't wax because the laser won't see the hair follicle. You have got to shave and then use it on a clean, oil free skin.
By the way, I tested to see what happens if you don't bother shaving at all, and I don't recommend it. It burns the hair and stings a lot. My recommendation is don't be lazy shave and laser right away :-)

Don't wax because you rip the roots of the hair out by waxing. You want to shave and that way the roots get killed with the treatment.

Yes! I even use it on the hair around the nipples and on the tummy.

I have had my unit for 1 1/2 years, still going strong. This is not cordless so there is no charge time. Never used TRIA so can't compare. The SensEpil does have a pretty long cord. I have personally gone through a LOT of cartridges and still have quite a bit of hair to remove. It has become pretty expensive.

It is permanent. You need about 8 treatments or so. The darker your hair the better it works.

Comes with 3 cartridges, one pre-installed and two replacements.

It treats a 2 cm x 3 cm area with each flash. You can grid your leg with white eyeliner to get a rough idea how many flashes you will need per treatment. It will take about 8 treatments to eliminate most if not all of your leg hairs. The first 4 treatments are done 2 weeks apart, the subsequent ones are a month apart.

Once a cartridge is completely used up (after 750 or so flashes) the machine won't work until you put a new cartridge in.

Not really. This is perfect for people with dark hair and fair skin, like me.

The darker the hair the better the results, so people who are tanned but have dark hair may see results, it might just take a few more treatments and sting a little more than people with fair skin. I have a birthmark and it stings on that spot, but the rest of the body is like a gentle snap from a rubber band or a little heat, but nothing painful and definitely not comparable to the pain you experience from waxing. In fact I can't imagine waxing ever in my life again, this treatment is faster and pain free compared to waxing.

I bought this machine 2 years ago and after 4 treatments my hair was totally gone for 18 months! When it did grow back, it came back in patches and the hair was much lighter, you could barely notice the hair. For me this is a miracle, my hair used to be extremely thick and dark it was embarrassing, and waxing was the only option for me, even though it was expensive and inconvenient.

My hair growth was so minimal after 18 months, that I didn't bother with another treatment for a whole year, but after shaving every now and again I began to notice the hair coming in more and growing a little darker again, so I started up my first treatment again last night.

This will not work on fair or light hair. It works on dark hair on medium skin tone. I have this and it works on my brown hair, not the grey. Will not work on my daughter who has light brown hair and fair skin.

Since it works on pigmented hair, the more pigment it has the better it works. I have read that people got ok results with lighter hair as well, but needed to treat more times.