The "SSD issue" is a rather simple one.
Unlike with magnetic disk, where there is no penalty in flipping a bit to write data, an SSD uses flash. To write to a flash memory cell, the whole cell has to first be erased. And a flash memory cell is many more bits then individual bytes on a traditional hard drive.
What this means is, that when you first get a flash drive it's full of empty cells. You can write at top speed because all the cells are empty. Indeed, when I first got my Intel SDD way back when SSD's were pretty new and TRIM was unheard of, at first life was great! The SSD was all it was billed to be and more! My Windows XP laptop booted in under a minute instead of 5, applications launched in seconds instead of minutes. I was ecstatic!
Until after a few weeks, the SSD started slowing down. Eventually, it was slower than the drive I replaced it with
And then the whole issue of flash memory cell size and the fact that a whole cell has to be erased before it can be written to surfaced as the cause for the slow down. What happened is, I had been using my SSD long enough, and written enough data to it, that there were no more 100% empty flash memory cells. Whenever I needed to write data - for whatever reason - the drive had to read out the data in a partial cell, erase it, then write back the data that was there plus the new data I needed to save.
It's a double whack performance wise since you have to read the data out of the cell first, then write the data that existed plus the new data back. What's worse, the data the drive is reading out of the cell may not even be data you care about any more. In all modern file systems, when a file is erased, the only thing that "happens" is the OS updates the directory of files. But the bits remain on the disk where they were, it's just that the OS will overwrite them the next time it goes to save a file. This is why file recover programs can undelete a file you permanently delete via the OS if you run them before the portions of the disk where the file existed get overwritten by new data. The rub is the disk, at a low level, has no way of knowing any of this. It's "blind" to what goes on at the file system level. To the hard drives controllers, all bits are precious and must be preserved.
Eventually the understanding of the fundamental difference between magnetic disk and flash based SDD when it comes to writing data spawned one of two paths to ensure that there is a steady supply of totally empty flash cells to write to so you have full performance. One strategy is TRIM - which allows the OS to communicate with the SSD at a low level and tell the SSD what data is safe to erase. This allows the SSD controller to shuffle flash memory cells around to ensure there is a steady supply of totally empty cells to ensure top write performance. Without TRIM, a drive simply has no idea what data on a drive is good or not, and as the drive is used more and more there may not be enough partially filled cells for the controller to consolidate to provide empty cells for peak performance.
Remember, it's not a function of how much free space you have as reported by your OS. That's an illusion presented by the operating system and file system. From the disk drive's perspective, all bits written to the drive are valid and must be preserved. TRIM solves that by giving the SSD controller insight into whats going on at the file system level, allowing it to do garbage collection and flash memory cell consolidation by throwing out data that is no longer relevant.
The other strategy is to build in an extra amount of space that is reserved for garbage collection. If it's a 100GB drive, then there is say 110GB of capacity, but that extra 10GB is never exposed to the computer - it's hidden by the drive controller and used exclusively to juggle blocks on disk in idle time. Very similar to disk defragmentation, but this time it's defragmentation of free flash memory cells. Partially filled flash memory cells are consolidated into completely full memory cells, and the partially filled flash memory cells are 100% cleared so that write's can happen at maximum speed. There is no need for TRIM or to know what is going on at the file system level as there are plenty of extra flash memory cells to allow the controller to do this, even on a completely full disk.
That's the tack taken by drives like the OWC Mercury Extreme. The downside is the extra cost in having extra flash built into the drive that doesn't count as useable space - it's just overhead. The upside is, since the drive does the consolidation of the flash cells internally, and it has plenty of free flash cells to do so, it's totally OS agnostic. It will always work, no mater what is running on top of it, no matter how long the drive is in service.
I have an OWC Mercury Extreme, it's been in my Mac Pro for over five months and I have no slowdown. I couldn't be happier with it. Personally I couldn't care less if OSX never gets TRIM support
Rather than wishing for TRIM support, which hacks the SATA protocols, which are hacks of the ATA and even earlier disk protocols that are over a decade old - remapping new technology over and over on to extremely old and now severally outdated concepts such as heads and cylinders; what we really need is a new interface to replace SATA and file system that intrinsically understands and can compensate for the differences in flash based SSD vs. traditional magnetic disk.
Then you really won't need fancy tricks like TRIM - it will just work - and at far higher performance levels than we are seeing even now.