This is tricky to recommend broadly, but easy to recommend if you've been looking for a good deal on the SB-Elite model. I start off with tricky, because the stated model (SB-30) is not listed on the manufacturer's website, and the Costco product page is lacking on the product specifications. After much research and close inspection, the SB-30 listed and the SB-Elite appear to be exactly the same, with the name on the label being the only difference; dimensions and appearance are otherwise identical. This is definitely the larger residential model (home size up to 4000 SF), when compared to the cheaper / smaller SB-75. The nearly identical SB-Elite runs almost $400; the normal Costco price for this SB-30 is $260, so for $209.99 this is a no-brainer. Am I 100% sure there is no mechanical / performance difference between the SB-30 and SB-Elite? No. But all the research I've done points to this being a rebranding effort, and the price difference is enough for me to take the leap.
More info on the SB-Elite, for comparison purposes, is here:
Another reason why this is tricky to recommend? I have no idea if it really works. Read the product page above for the sales pitch, but essentially it uses electrical currents to alter minerals in your water in such a way that it cuts down on mineral deposits in your pipes. I've held off buying this for years because my phony-baloney radar goes off, and reviews are quite mixed, but I've seen enough good reviews and testimonials with photos, and my home issue with this problem is relevant enough, to where I've been willing to try it for the right price. My suspicion is that it works, but the effectiveness varies a lot by individual home characteristics, like water supply mineral composition/concentration, pipes, proper installation, time in use, etc.
One other interesting note is that the company won't honor the warranty to their products if you buy it from Amazon or eBay, so I feel a little better that I'm getting it from Costco.