For what you are looking at using the rod for, it is a very good value and you wouldn't go wrong with it. You can use the shorter rod for torut out west and for smallmouth; just keep in mind that it requires more work to cast a short rod over 45'-50' and that it takes more work with the lighter line 4 wt to cast flies larger than #12 than with a 5 or 6 wt. I'd be inclined to get a 7'6" (possibly 8') 5 wt instead of the 4 wt because it will handle the bigger flies used for smallmout and handle wind on the large western rivers better than the 4 wt. A 4-piece 7'6" or 8' pack rod is not necessary unless you are going to be using the rod a lot on backpacking trips. Therefore, I'd get the 2-piece like you dad recommended.
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