I personally don't collect the modern stuff because to me I just don't find them at all interesting, or even worth pursuing. That is just my personal opinion though. I do enjoy the kaleidoscope flowers as I think they're fun to look at.
I mainly collect the US Classic singles & covers also, classic era B.O.B. items.
I stopped collecting U.S. stamps effective 1993, which was an arbitrary stopping point given that's where my album ended at the time. It's about the time that the USPS started actively screwing collectors by releasing a ton of useless stamps to try to get more money from the collector market, and the design quality of US stamps has fallen off dramatically since that time. Personally, my opinion of the 2013 stamp program is that it's even more garbage than the 2012 stamp program.