I used to use the Eyelure individual lashes but with professional glue, you can get it at sallys for about £10-£30 it's in a very tiny bottle but one bottle lasted me two years and I wore them three weeks out of every four. They would last about a week before I would remove them with an oil based makeup remover then I would remove ALL traces of oil and reapply. The reason I would have a weeks break is that I tended to wear them on the outer half of my lashes and after three weeks my lashes would start to thin.
I know this is primarily about individual lashes but my glue went off before it ran out (it lasts that long) so I decided a change was in order. I now buy Ardell strip lashes for just over £3.00 a pair from Sallys. One set lasts about a week to ten days (if looked after and I'm now a pro at applying them each day (I wear them 6-7 days a week) they do some very natural looking lashes and they have invisible bands but they are still not as natural looking as the individual lashes but at least I get to wear them all the time.
I use the eyelure striplash glue (£2.50 at boots) as dispute hearing rave reviews for the Duo lash glue (£8.00 at sallys) I find my lashes NEVER start falling off and are still in place at 10-11pm when I take them off and most importantly it it easily removed from the lashes without damaging them ensuring they last a long time.
So, that's my take on both kinds, it you don't want the maintenance and daily application then individual lashes (by individual I mean the sprigs of lashes, I never tried the single hairs but imagine they are similar) are fantastic and with practice will look very natural. You do on occasion have to fill in the odd gap especially if you are an active sleeper and you may find your lashes thinning.
If you want an instant look you can change everyday and (for me) is kinder on the eyes, strip lashes are great. Downsides are the daily maintenance and removal before bed and also you do have to wear eyeliner to blend the strip but with practice this isn't always necessary.