quick list of mentioned issues from an owner of a 1300.
1. throttle jerkiness at slow speed.. ivan's tune solves this issue. Ivan's Performance Products
Best upgrade for the buck !!
2. front end clunk over bumps.. this was mostly the pre 10 models. they upgraded the front springs.
3. oil filter removal if using stock filter pre 10 model. filter is a stubby so hard to get a wrench on. newer bikes got a longer/higher capacity oil filter.
4.oil level site glass location. hard to see as the bike has to be level and not on the side stand.
5. Handle bars too wide.. they did improve them after 2010 model but most still upgrade to the RSTD or equivalent as they are narrower and cause less shoulder strain.
6. on deluxe models the front fairing is known to rattle if not secured properly and the rubber gasket between shells is not installed properly.
7. leather wrapped OEM saddlebags are not very well sealed or waterproof.. hence the drain holes in the bottom from factory.
8. heel toe shifter not setup well for using as just a toe shifter. larger feet tend to use toe shift more . easily adjustable.
9. wiping the grin off your face when riding with HD riders and your a little more comfortable with less vibrations and you can keep up easily.
FYI no fuel gauge but i usually can travel 50 miles after the fuel light comes on but I wouldn't push it much further.
Hope this helps a little to the OP.