Harmonia Mundi are HIP specialists, so it would depend if you like that, how much of what you already own is HIP, etc. Their recordings tend to vary as far as performances go (IME more hit than miss though I tended to be selective of well reviewed discs from reviewers I trust, so there is some selection bias) and recording quality is above average. Here is a more detailed breakdown of the contents: Lumieres - Music Of The Enlightenment [30-CD Set] - Harmonia Mundi: 2908601 | Buy from ArkivMusic IMO for me it would be a more interesting box without Beethoven, JS Bach or Mozart, because like you I already have plenty and either have performances I like more than what is on that box or performances that I am completely satisfied with and don't feel like I need another HIP version.
I haven't bought the Herreweghe box, but one of the first mega-boxes I bought was Harmonia Mundi's Sacred Music. A good overview from Gregorian chant to the 20th century. It is mostly early music and baroque. It's still available on Amazon, surprisingly since it came out 8 years ago. https://www.amazon.com/Sacred-Music-Various-Ltd-Box/dp/B002HNA9LS
The first time I 've heard the term HIP was on this forum. Back in the day, we used to call these "period performances".
This is now available from .com - https://www.amazon.com/Deutsche-Harmonia-Mundi-Great-Recordings/dp/B0765S8NY4 I'm expecting my 3for2 order tomorrow from .de with this set in it (EUR80 from .de) 3 disc overlap with the DHM Christmas Edition - not bad, giving the overlap to the inlaws
Hans' link explains it very well. If you have the big UMG Mozart box from last year there are many performances that are HIP as well as the same pieces performed by the non-progressives It was some classical reviewer that first used "progressives" in a snide derogatory manner for those staunch HIPsters
‘73 was a great time to be young. My cello teacher had this chick in his house with a different last name (and you know it smelled funny when she was around) and she played the viola da gamba. You just knew it was because she would never play cello as well as any of the men. This was my introduction to “historically informed performance practice.”
Actually, anytime is a great time to be young... To bring this diversion back on track, the mega-box track that is, obviously the young woman's name was not Jaqueline du Pre. Few men played cello better than she.
Back to the big Rudolf Serkin box - am now listening to Beethoven: Piano Sonatas 8, Op.13; 14, Op.27/2; recorded in NYC, 1941-1942 and 1945. Disc 2.
I got mine through Amazon.uk, at B.I.C.'s recommendation. Cost me approx. $750.00 USD total (ordered in British pounds.) Maybe try there if it doesn't show up elsewhere at a lower price.
It would be approx. $100 cheaper from Amazon Germany right now with standard shipping. Cost is Euro 503.36 with four shipping options ranging from Euro 50 - Euro 70 (approx.). XE.com converts the Euro 553.51 price with standard shipping to $656.63.
This is one of the few sets that I would trust to be not damaged going through StandardShipping because it is so well packaged. Typically I choose the shortest shipping time cause the longer it is in transit, the more chance for damage. It usually pays off.
Of course, the above prices all assume that such a costly box gets through Customs without getting dinged for sales tax!