HMB? Host Memory Buffer? On a SATA drive? LOL. That's for NVMe SSDs ONLY, because they are connected via a high-speed, low-latency, PCI-E connection.
SATA's a little bit slow, and sector-oriented, for that.
(AFAIK. If there is a HMB drive for SATA, please let me know.)
That being said, SATA SSDs with DRAM cache for the mapping tables ARE a bit faster than those without, especially for random writes. An SLC caching portion of the drive will also speed up writes, and lower write amplification slightly.
I like the performance of the Adata SU800 Ultimate drives, even the 128GB capacity units were fairly speedy to my experiences. (I use them in my personal rigs.) They were a first-gen 3D NAND drive, and have DRAM and SLC caching.
They aren't the cheapest, though.
Recently, Newegg has been running sales on the PNY CS900 SATA SSDs, 120/128GB for $29 or so. I picked up a few at the beginning of this month, but I have yet to actually try one out. I bought them based on price, and the fact that I trust PNY more than Team Group or Silicon Power. (Although I do have a Team Group 480GB L5 Lite 3D NAND SATA SSD in this laptop I'm currently using.)
Edit: I thought that you were talking about a 128GB Mushkin TriActor 3DX. Now I realize, you're talking about the 500GB model for $79.99 on Newegg ShellShocker today. That's really not a bad deal. I've seen the Team Group L5 Lite 3D NAND 480GB models for $69.99, on a sale, but for the price, that Mushkin's not bad. (If you can stand Mushkin, I had a failure with one of their rather older SandForce 2nd-Gen drives, probably a firmware issue. Those were kind of buggy, though. Modern drives with Phison or SMI controllers should be more stable.)
Another budget-oriented drive that you should keep an eye out for is the Toshiba / OCZ TR200 240GB SATA SSDs. I've seen them as low as $39.99, I think, or at least as low as ~$43. Normally, they go for around $60. I've used a couple, not extensively / daily though. They are DRAM-less, so they should be cheaper.