Large HDDs will often beat an SSD at raw throughput. This is not where SSDs have an advantage. Where they have an advantage is reading and writing small amounts of data all around the drive. This is because the time taken to access a single cell and return the data is basically equal across the drive, and extremely fast (in the order or 0.1-0.3ms usually). HDDs must reposition a mechanical drive head to randomly read or write, and this often takes over 12ms (Raptors are usually less I think). For small random reads and writes this can mean the difference between 20MB/s on a slow SSD and 0.4MB/s on a typically 7200RPM HDD.
If all of the data that you are reading or writing is sequential, such as with unfragmented large files, a HDD does not need to reposition the head constantly and can perform optimally. An SSD is also very fast, but it loses its advantage because its biggest differentiating factor, access time, does not negatively impact HDDs in sequential transfers.
What are you using to do benchmarks? If you are using HDTune use something else
Crystal would have shown you 4k random reads and writes as well, those are what you should pay attention to. The stated specs are always mentioned right after the phrase "up to" which means that in theory it is possible, but in practice unlikely. Also, those specs are reached using ATTO, not Crystal, because ATTO typically provides higher numbers. It's standard practice for manufacturers to show off their hardware at its best. I would check if the SSD's packaging and manual actually state 375MB/s as well, because the specs can change as new firmware is added and Newegg will almost certainly not update their page to reflect this. Normally newer firmware reduces performance marginally because it includes additional error-handling code or improved wear levelling, all of which increases load on the Sandforce controller.
I would have got a 3TB if storage is what you were planning on using this for. If you were planning on using it for your OS then a 3TB HDD isn't even in the same league as an SSD. Windows doesn't perform sequential transfers.