The first linked Thunderbolt enclosure,''' the Seagate Backup Plus Portable Thunderbolt Adapter, is limited to ~320 MB/s read speed and ~380 MB/s write speed.'''
For me, this was much faster than the base 1TB 7200RPM HDD; however, '''I bought the brand new Samsung 850 Pro, which is rated roughly 550 MB/s read and write speeds.'''
So, keep those limits in mind when buying a thunderbolt adapter.
'''I cannot comment on the Delock.'''
I read that the '''Lacie Thunderbolt drive had a much faster I/O limit''', and one just removes the original Lacie HDD included inside the enclosure.
I'm researching now wether or not I can just remove the included 1TB HDD and replace it with my 2.5" SSD with the appropriate 2.5" to 3.5" bracket adapter.
I'll update here.