I have to say that I am not a fan of changers, practical as they may be - and from the various approaches to the problem, carousel would be my least favorite. Lots of plastic suspended on very little area, many parts that can resonate...
Regarding a mod to a cheap SACD, things can certainly be improved a lot.
I am now on my secod Pioneer 656 multistandard, and it is a very modifiable machine, very cleverly made, too. I modded one of the very first DVD/SACD budget players from Sony for a friend and it has been his mainstay player for the last 2 years. Before that it was a $200 Sony CD player from around 1995, also modded.
It helps to understand that these are really designed from the top model, and then sort of 'stripped down' to cost. Essentially, the electronics is mostly capable of everything the top model can do, provided all the ancillary components are provided in the propper manner. One thing that remains is the mechanics - when scaled down in cost, longevity suffers, and there are almost no ifs and buts about that. As Yamaha B-2 mentions, the old X777 and 707 CD players are still considered the best transports available, even after 14 years - while there are very few then-budget players left today with their transports still standing.
Also, there is something to be said about diminishing returns. I don't think I ever put more than perhaps $60 into a budget (and sometimes not so budget) mod. The trick is spending where it counts, and you would be surprised how far $60 can get you. I don't think I would be prepared to put more than the worth of the original component into mod efforts, so for me a $550 mod on a <$200 component is excessive - but that may just be me. I tend to look at what is actually modded without the 'black arts and voodoo' approach... I would have been very interested to read what the mod is about, but the linked 'review' will rather talk about how the car steered itself to Circuit City, and wax appologetically WHY an audiophile went to buy a budget component in the first place. There is really NO info about the mod at all. And, lets be honest, a review which compares SACD players by which one 'sucks less' sounds just a liiiiitlle biassed to me...