Product review (4 stars): the trade-off is it really looks nice. We have bought an additional (back up) unit ...
We have used this cooktop for just over 3 years. Yes, the glass is difficult to keep clean, we anticipated this when we bought it, the trade-off is it really looks nice. We have bought an additional (back up) unit in storage for future, we were concerned about changing the opening size in our granite counter.  We already priced the replacement glass and saw it was nearly the price of a new cooktop complete, so we are prepared to switch it when it is necessary.  The operation is very good but we do not do much canning any longer, it would be messy for clean-up if we constantly had a full-size family around. Some day, I anticipate the glass will get cracked, I am ready to just drop in the new unit we have and move on.