The MGM DVD is a disappointment.
Like the Warner Bros. Archive Collection, MGM is now releasing some of their "lower profile" titles as burn-on-demand DVD-Rs. And, like Warner Bros., the quality of source material is very hit and miss. Curiously, the MGM DVD-R of HOUSE OF LONG SHADOWS doesn't look as good as the print currently being used by TCM. (Even the old VHS of this from MGM appears to have been taken from a better source.) Unfortunately, unlike DVD releases, the films used by both Warner and MGM for these DVD-Rs do not get cleaned up for transfer. Supposedly this practice, the lack of any bonus features, and the use of the DVD-R format all allow the studio to keep their costs down. Sadly, they don't pass those savings on to the consumer. (SRP for most of these DVD-Rs tends to run higher than that of many regular DVDs.)
If you are considering buying any studio DVD-R release along these lines, try to check out the reviews for that particular release first and see if the title you want is one of the ones that used decent-looking master material.