I can confirm this as mine was running sluggish and slow; BlackMagic speed tests revealed below 100 MB/s and kept fluctuating lower and lower with every read. Once I enabled TRIM using that program, it is back up to 400-500 MB/s but sometimes it fluctuates down which is weird, don't understand why that is happening.
I am running a MacBookPro (mid 2012) with a Samsung 830 ssd and right after I installed Yosemite, I tested the ssd with the Black Magic app and consistently got 510mbs/read and 445mbs/write speeds. I left TRIM OFF for 4 or 5 days (not sure I wanted to deal with the Kext-signing issue) and restested the ssd. The speeds had lowered to 405mbs/read and 335mbs/write speeds. Lastly, I have turned TRIM ON now and I am right back to where I use to be. There is no question in my mind it made a huge difference in speed in a fairly short period of time. By the way, I am using about 50% of my 256gb ssd.