I tried the first TRIA (laser) and the first Silk'N (IPL). Those first models didn't even have clever names!
TRIA was fairly painful when the laser was on, like a searing burn, but the pain didn't linger. Unfortunately it only covered a very tiny spot at a time, much smaller than a US dime.
Silk'N had a flash lamp that had to be replaced after 750 flashes. It could hit a fairly large area compared to the TRIA unit. Its cooling fan was very loud, like a hair dryer -- too loud to watch television or carry a normal conversation. It took annoyingly-long to recharge between flashes. (Flash. Wait. Wait-wait. Wait. Flash.)
Both units yielded a decent reduction in hair, but neither was completely effective.
Last year I bought a Braun Silk Expert Pro 5, and I splurged on the top model because it had the fastest recharge time. (The less expensive Pro 3 takes about twice as long.) It's quiet enough that it won't disturb anyone. Treated hairs fall out in about a week. A few straggly hairs came back, but treated areas are mostly clear after a few months. Suggestion: choose the fastest model if you can afford it.
Because it only affects actively growing hairs you will need to repeat the treatments no matter how you get it done, even at a salon. Even electrolysis has to be repeated a few months apart in order to reach each follicle during its active-growth cycle.