A few years ago there were supposedly bad ignitors used by a number of brands of high end ranges - to the best of my knowledge they were replaced by the manufacturers and now a different, better kind are in use. In my case on my DCS range, the ignitors would continue to click after the burners were lit. Since the ingnitors were replaced I haven't had the problem. The repair person explained to me that the old ones weren't the correct height and didn't always detect when the flame was actually on. I remember reading that Bluestars may have had a different problem with the ignitors spontaneously clicking even when the range was turned off - you can check the Bluestar threads to see how that was resolved. I agree with the previous poster - if your problem is just with the ignitors and I would start with getting them replaced rather than trying to rebuild the whole cooktop unless you have other problems.

The AG's have a red light on the front that goes out when the temp is reached. It will go on and off as/when the gas cycles on/off to maintain the set temp. FWIW, we noticed our oven took longer, too, and the calibration checked out fine. It could be the learning curve of a new oven (e.g. old oven running hot) and it could also be going from a 30" to a 36" oven in our case. We suspect that food cooked in a larger oven cavity might take longer than in a smaller oven cavity. Think about it, a slice of pizza re-heated in a toaster oven heats up much quicker than in a regular oven, so it could be the same type of thing. If not, I have no clue.

I've had the soon-to-be-discontinued open burner, all gas 30" for a week and a half, so too soon to know about problems or long range reliability. I bought now because I prefer a more open burner pattern. I roasted a turkey and made gravy the other night and held the gravy on the super teeny middle burner without any problems with burning or scorching or a hot spot. The door is definitely warm in places (particularly behind the handle area), but I had been purposely running my hand over the door wanting to see if it was really hot (I too had read about the same problems you are mentioning, and my husband thought I was nuts to do this). It certainly doesn't stay hot for an hour though. We replaced an old dual fuel Jennair with much less power than this one, and our kitchen definitely seems warmer now than before because of the venting of the Wolf's non self-cleaning oven (we had self-clean and electric oven before). But, we also don't have any ventilation hooked up yet. So far the top has cleaned up quite easily. The turkey had spattered as it roasted, and my husband wiped out the inside of the range, including taking out the side rack supports so he just had a clean swipe to do. He said it wasn't too bad cleaning it up, but he can see how keeping on top of this is the way to operate so it won't get too bad. And, LOL, this is the first time in forty years of marriage he has ever cleaned an oven! I'd try the appliances forum for more comments.

I think the answer depends on how up market or down market the house is. Is the house a medium to high level of "nice", and in a neighborhood of similar houses? If yes, I wouldn't skimp on making the renovation a complete job. Newer equipment will operate more efficiently and the open walls will allow a good contractor to make the system operate at its best. A 20 year old HVAC system has its best days behind it. If it's a down market house, then like a car of similar description, most would continue to "drive" with a "will fail any day" HVAC system until it quits. I live in coastal Central California, replaced 20 year old equipment 20 years ago when I did a major remodel (glad I did) and am getting ready to replace the replacement (so that I can do it on my own terms during a non-peak season). Good luck.