Hibernate (S4) uses no more battery power than a standard shutdown (S5) does, and there is no lack of 'clearing of the memory banks' since the computer essentially powers off after a hibernation, and the memory is cleared because it's volatile and receives no power in the S4 state. You can theoretically hibernate your computer, unplug it for 50 years, plug it back in, and resume without a problem (because all the data in memory is stored to non-volatile disk, not suspended in volatile RAM like standby/sleep does).
Hibernate takes what's in memory and saves it to disk, and then shuts the system down with the instruction to take what was stored from RAM to disk, and move it back from disk to RAM when it is instructed to power on, thus 'resuming' your system to its' previous state.
There are no ill effects from hibernating, except from the occasional program that suffers from memory leaks (example: FireFox). If it stays open, that program in memory (in all of it's bloated goodness) will be saved to disk and restored back to RAM when you power it back up. That can cause programs to use more memory than they would if they were occasionally restarted (which might not happen if you are always hibernating).
In other words, you shouldn't notice any more performance difference when choosing to hibernate than you would, say, running your computer 24x7 without ever restarting.
I also prefer putting my laptop in hibernation when I'm not using it (like overnight). Standby modes also work very well in modern systems since modern hardware is so efficient. Just about the only piece of hardware that remains powered on in standby is the RAM. I usually use this when I am traveling short distances (on foot). I can put my computer in standby mode, and throw it in my backpack. It can stay in standby for hours, maybe even days on a full charge before it runs outta juice and hibernates.
For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth