Well there has been micro blocking in some pressings and the blacks can be poor. There blu-ray pressings in the past few years have been very hit and miss. Some pressings great, others not so great.
Poor compression on some of the titles and microblocking. Some of their titles I purchased were simply not up to scratch. They tend to be mixed bag these days. Some are superb pressings and others poor. For example "In the Heat of the Night" was great but "Kiss Me Deadly" had a lot of compression problems with blacks looking grey and a slight judder in some scenes. I suspect the actual masters are great but the encoding house didn't do a great job.