If you can afford the better shifter, definitely do it! If you can feel and notice the better quality (especially since you are an experienced biker), you will regret going cheaper, especially since you plan on having this bike long term. The more you enjoy riding your bike, the more likely you will bike and stay fit for years to come!
2014 Liv Lust
2013 Specialized Fate Expert with carbon wheelset (sold)
2012 Specialized Amira Elite
2010 Santa Cruz Juliana with R kit and Crampon pedals (sold)
2011 Specialized Ariel Sport,suspension post,Serfas Rx Women's Microfiber saddle (sold)