I haven't tried magnetic lashes on myself. When they first came out, the style was a set of two (2) lashes that both went on the top lash (these still exist). One went 'on top' of the natural lashes and one strip went underneath the upper natural lashes. It was made this way because each strip had tiny magnets on them and they were meant to stick to each other to secure or 'anchor' the lash.
I've experimented with the 'original' style on clients that had purchased them on a whim and never used them until I opened the box. First, the tiny magnets don't go all the way to the ends of the strip, so the ends can lift up on the inner and outer corners. Next, they are literally impossible to put on -- the original style that is, that you don't use eyeliner with. Third, I can't imagine feeling comfortable for a long period of time with a false lash under my natural lash and that close to my eyeball.
Fast forward to now -- new and improved magnetic lashes. I say new and improved because they come with magnetic eyeliner to adhere too, instead of the magnetic lower lash. So dealing with one lash is already better. Then, not having to align tiny microscopic magnets perfectly now and instead just laying it on a magnetic line makes is much easier to apply. This also eliminates the worry that the corners of the lashes will lift up, accentuating the 'false' in false lashes. I don't personally wear false lashes (see my post on 'My Favorite Mascara'), but I do work on many clients that wear them (extensions, strips, individuals, magnetic). I definitely recommend falsies for special events, they look amazing in professional photos.
Lets look at some pros and cons:
You have to have a level of comfortability with liquid liner.
If you prefer a very thin liner, the lashes have less product to adhere to.
If you have a liner you love, you can't use it -- you have to use the magnetic line they come with.
They are reusable.
They won't pull out your natural lashes.
They are easily removable at nighttime, so you don't have to worry about not getting make-up remover, etc. on them.
If you find using lash glue difficult, or are allergic, this is a great alternative.
Chose a less dense style -- meaning the lashes aren't so thick that you can't see your eye shadow through them.
Don't load them with mascara.
Use the eyeliner at a medium to thick thickness and line the entire upper lash line.
Get the full strip, not the half strip - they blend with your natural lashes so much better.
Don't forget to trim them to your eye size so they look as natural as possible.
You can get a decent pair between $15 - $30 US dollars. There are ones less expensive and ones way more expensive (think $70+ per pair).
I'll keep you posted with more magnetic lash updates as they come -- only time will tell if they are a fad or will be around forever!