ok ... all useful and civil comments and suggestions. I will buy the idea that future proofing is folly. It may be just another anxious way of framing the issue of what is the better choice for now given an uncertain future. Two heart attacks later, I appreciate how uncertain the next day may be, so buying for now and adjusting when and if there is a five year future is probably the best bet. I will probably get one or another compact, which ever can be maintained easier by some LBS, with the lowest gearing that is available. If the hills hurt my knees, then I will walk. It really is not about strength, I have enough of that. The issue is managing the strength so that I do not hurt my knees and then riding will not be an option. These are very helpful comments and I appreciate the thoughtfulness of all the questions and replies!