tldr; maybe try the refurb first, try it out under your most intense regular usage sessions, and if you feel annoyed, return it and spring for the faster one, wash rinse repeat (assuming you can return it). I can tell you now, that annoyance never went away for me even though I hoped beyond hope that it would, since the Macbook was basically the laptop I've been waiting for for nearly 10 years. The Macbook performance rides that thin line that divides "fast enough" and "not fast enough" vs "fast" and "faster" and if it falls on the wrong side, it won't be $300 you're saving, but $999 you're losing.
the nitty gritty; I'm apparently one of those rare few who bought the original Macbook and was just disappointed enough at the performance to be willing to try upgrading to the refreshed Macbook. I've used Macbook Air's for work for a long time and never had an issue, thought this would be the same, but it's not.
Despite burning $1500 or whatever for the mid-range Macbook, thinking it would be "fine" for web browsing and casual coding/spreadsheet work, it turned out to basically be a waste of $1500. It's given me so much grief with all the visual stuttering, sporadic third party bluetooth compatibility (Yeah I know "use a magic mouse." Too bad the magic mouse can't track on my desk surface. Yeah I know "use a mousepad" at that point in time I may as well just "use a Macbook Air" instead of using a Macbook). Long story short, I just ordered the highest performance version of the refreshed Macbook, am going to see if it loses all the stuttering and wireless dropouts (which I might add is really really important for a computer with only one physical port) and if it doesn't, I'm returning it and switching back to my 2015 Macbook Air which, while it's uglier, has a lousier display, has a better keyboard and stable wireless mouse connectivity. Turns out prettiness and not seeing pixels on my display are awesome, but not dealbreakers, whereas constantly missing keystrokes due to the shallow keyboard and having to wait for 30 seconds every hour while my bluetooth mouse reconnects are. (Yeah, I know "just get used to the keyboard, you're using it wrong" well try "getting used to it" at 180 wpm when you don't have the same amount of free time you did when you were in middle school learning how to type).