So, I finally decided to upgrade my old MacBook Pro (a 5,4 from mid-2009) with two Samsung 840 6G SSDs (based on the new - for SSDs - TLC NAND technology), one in the main bay and another in an Optibay: everything works perfectly, and they both negotiate at 3G (the maximum possible for that SATA 2 machine), also the one in the Optibay.
Currently, I would try a configuration like this: OS X and users in the main bay SSD, and VMs stored in the Optibay SSD, which should be ideal for maximum performance (on independent controllers).
But, especially being that those are TLC SSDs, which seem to have less endurance than the traditional MLC SSDs, I would like to minimise the writing of big files and such things; BTW, I found this webpage:
http://artykul8.com/2012/06/vmware-performance-enhancing
... which contains some possible tweaks, especially the vmem one.
In particular, this:
For VMware Fusion on Mac and Linux instead of mainMem.useNamedFile you have to set mainMem.backing flag.
VMware Fusion Config files are located at: /Users/username/Library/Preferences/VMware Fusion/preferences and/Users/username/Library/Preferences/VMware Fusion/config
mainMem.backing = "swap"
Is this really true also for OS X (Fusion), besides Linux? Would the virtual memory be stored in RAM (I have 8 GB), thus?
What other tweaks could be essential for a longer life for that type of SSD? Of course, you cannot avoid suspending and resuming a VM, but other things?
Thank you all for any possible help - of course, I really wouldn't want to prematurely ruin an € 300+ SSD (with a new, but also potentially worse TLC technology) before time, if it's really possible to make it last longer, with some "sweet" and thus not too disruptive methods... 
BTW, now, shouldn't Fusion - in the new era of SSDs - auto-detect if VMs are run off an SSD and thus apply the maybe necessary tweaks, and automatically...? 
Certainly, if possible (and it is, or isn't it? probably, some more "official" information would be rather more clarifying, at this point)...