I think they are worth it if:
A. Your button springs are wearing out/ getting loose
B. You want to rock a heavy atty and not lock it when you set it down on a table. (my reason)
Otherwise, I didn't notice any "OMG I got to have it" performance improvement (Feel)
[MENTION=56]jkuro[/MENTION] performed his voltage drop tests with and without the magnet upgrade in the button.... no change in voltage drop, so they aren't going to make any changes to your "vape".
the button feels A LOT better. That was my main reason.
if you get that crunchyness from pressing the button, that also goes away. that was why i was very happy with my upgrade.
springs can collapse if you run really low ohm setups. if its the weak point in the mod (usually the case), they will heat up and collapse. magnets never will. downside is, a hard short will probably fuck up your battery, as opposed to collapsing the spring.
i only use magnets.