Honestly this MX300 is one of the most interesting SSD's on the consumer tier right now.
Price/GB is getting a serious drop from one of the most notable SSD companies, this is an example others will be forced to follow. The good name of the MX line is in the consumer's advantage even though its performance is lower than the previous drives.. For example, you can be dead sure Samsung is going to want to position something at the same level, and at least similar performance because that's what is selling their EVO's right now (similar price, better perf - even though nobody could ever notice the difference in perf).
FWIW the only SSD's I would ever consider are Intel, Samsung and Crucial. All the rest have had extremely questionable SSD's in the past and are not stellar in any way, neither endurance nor performance nor Price/GB.
This hasn't changed.
About SSHD, this is usually a form of SSD caching, and will only be close to SSD responsiveness when stuff is actually cached - that is - frequently used. Great for applications, worthless for data, and performance can be all over the place and differ completely per use case and even application. That being said, I also *feel* it is the least reliable drive you can get because it requires more parts, and each part can fail. It's cost effective and that is about all you can say of it.