Re: New iPhone much better than 6+
You have a matter of weeks before the new iPhone is announced...if you're itching to get a new phone so badly that you can't wait a matter of weeks, I don't know what to tell you. Will the new device be "much better"? That is all in what you consider "better"...the "S" model is always a significant update to the regular model in very tangible ways. Some people find the "S" model the one worthy of waiting for when their upgrades come around, and they skip the regular model (if that tells you anything).
So to answer your question...yes, the next model will be better than the current models. They always are.
Should you wait? Only you can answer that question...but to me, common sense would say wait a few weeks to see whether the new model is worth it to you...and at that point, you can probably get a 6+ a lot cheaper than even right now.