I could certainly be wrong but from the sound of your post you sound like someone who has "aspired" to have a SubZero fridge not necessarily for a functional reason but to have the brand. It sounds as if you're going all out - two Miele dishwashers, etc. - so why not just go for the SZ? If you think about all the people who have been keeping their food chilled without investing in SZ, there has to be something people "value" about SZ other than it's functional ability to keep food chilled or frozen that would make them pay the premimum price. Could be appearance, appeal of saying you have the brand, etc. In any case if you want one and want to spend the $ go for it. It seems you can count on repairs with any brand these days - kind of like luxury auto brands. Just because you spend alot doesn't mean it will be trouble free.

There's a third question to consider - the cost of purchasing a new refrigerator. That might help you make your decision. For what it's worth my 23 year old Sub Zero 501R (that's the 36" all refrigerator) wasn't staying cold enough, the temp would go near 50 for a few days and then return to normal for a week or two. After this happened 4 times in 3 months I called for repair. The technician came yesterday - he adjusted the temperature sensing tube which was out of proper alignment and adjusted the metal plate at the bottom of the door to make better contact with the switch. It's been cooling beautifully now for 24 hours. Since he was only here for less then 30 minutes he only charged the trip fee which was $80.00. I've been fortunate to find a family owned, reputable, authorized repair service and I've used them now for 15 years. I asked him if he thought my refrigerator was nearing the end of it's life span and he said that as long as Sub Zero had the parts he could gut it and repair it. That's good news since the replacement refrigerator and freezer are now taller and would require having my cabinets altered. If this fix doesn't work long term he'll replace the cooling switch - again not a big expense. Good luck with your decision.

Two comments: (1) We have an older model 532, which is a 48" side-by-side. It is our first sbs and we don't like the sbs arrangement. Both the refrig and the freezer sides are too narrow for our liking. Have you been able to see one in a store? (2) We have several previous posts in which we describe our totally miserable repair history with our SZ. Consumer Reports data also bears this out -- the worst built-in of all brands. It appears that you have some constraints on what you get if you put in an island. Have you considered a French-door model? KitchenAid has a 42" overall width model. Each of the upper doors would swing open about 21", yet you would get the full width inside. When our SZ dies (it's been on "life support" several times so far), we'd definitely look into the French-door layout. Good luck on your selection!

If you can get the floor models, it sounds like that is what you prefer, but if not I will add my plug for a 30/24 Thermador (or any of the ones they make and put a different name on). Does your current set up give you enough freezer space? I have a 30/18 combination (coming up on 9 years -- can't believe that) and would have loved the wider freezer, but there was only so much room. You could do stainless -- and if there is a chance you will redo the kitchen, you won't waste panels matching the old kitchen. I believe Thermador is delivering the units differently now (the panels were shipped separately), but I suspect you would still be able to change the stainless to cabinet panels down the road. I would at least make that inquiry if there is a chance of change. I have had stainless nearly 9 years with no regrets. I didn't get panels because we had thought we would have the dispenser and were cautioned against drips on the wood. We were given a loaner when the dispenser models were delayed and decided not to change it out. I haven't had any issues with the panels looking good since I learned the biggest problem is the cleaners people put on stainless (that's where the smears and streaks come from -- and if you change products it gets worse). I use a microfiber cleaning cloth with water and nothing else on mine and it has been much easier and looked better. Plllog mentioned redoing the kitchen -- if that is an probability, would it make more sense to repair the existing unit and leave all your options open for down the road? Or live with the combo unit until you do? Basic second fridge for half the price of the repair, use it during a remodel and then sell or donate it? I think your plans for the kitchen should be the major factor in what makes sense as far as the panel choices go.