Eros is what I use. As with anything, how you care for something dictates its lifespan.
You have to remember. Thin skin .03 were meant to last for 30 days. Many of us have gotten upward of 4 months out of them, which is great. However it was never its intended purpose.
Because of such, people now have an expectation of 4 months. Claiming it's a poor system If it doesn't last of that long.
Keep in mind the hair used is severely processed and stripped. Even if you go with a thicker system, let's say it lasts longer, you're going to have a worse hairline... And open up more problems. Which is the system turning red or green and losing color...and beat to death hair. What's the benefit?
I could be incorrect, but I doubt it.
You're doing this because you want to look your best, right?
Why play around over a couple dollars? You avoid all of this by replacing the system every 2 to 3 months...