When I was buying my first electric guitar I made a lot of research (because I always do). Having been a metal fan all of my life I found out I was pretty ignorant about guitars. I quickly found out that there are bunches of guitar makers, and more importantly two kinds of pickups. I was set to get a strat at first, but luckily I quickly was shaken out of that misconception and bought a Cort with two humbuckers, “inspired” by double-cut PRS’s.
After that other things gradually occured to me (usually through forums), like that there are different pickup makers as well, string guage, string action, volume and tone, fixed bridges versus floyds etc.
My newest insight is into guitar scales – as in scale length (not musical scales such as ionian or dorian). A guitar is a single-scale instrument, where the scale is the length of the string measured from the nut to the bridge. Other instruments with multiple string lengths such as harps have multiple scales.
I was first alerted to scales when I bought my Schecter Omen 7. It was really cheap in spite of a DiMarzio Blaze in the bridge, and when I asked the seller why he was selling he said the 25,5″ scale is too short for tuning down as low as he wanted. After  buying it I checked the specs on my other guitars: the Cort M520 is 24,75″, the Ibanez S470 is 25,5″ and the Schecter is 25,5″ (newer Omen 7s are 26,5″ though).
So, after buying it I read up on the why scale matters. Hoping I get this right now, a shorter scale guitar has lower string tension compared to a longer scale guitar, when tuned the same. This means tuning down on a longer scale guitar keeps the string tension higher allowing for low action and no string buzz and a tighter feeling. The same downtune on a shorter scale guitar requires a thicker string gauge to get the same feeling.
Scale also matters when it comes to what size hands you have. With smaller hands (such as mine) a shorter scale makes it easier to reach over multiple bands, with larger hands a longer scale allows for easier finger placements as the frets are wider. This sort of explains why I’m extremely comfortable playing my Cort and struggle a bit on the Ibanez (if I play that regularly though my hands get used to it and the Cort feels uncomfortable).
Scale impact on downtuning is kind of a touchy subject in the guitar community, maybe stemming from the two giants Gibson and Fender having different standard scales (24,75″ vs. 25,5″). When I’ve asked questions about scales and downtunings on different forums this has usually sparked intense discussion with cheap shots such as “you have to pick like a girl if you tune a 24,75″ to B with thinner strings than .70”. Longer scaled guitars (something like 27″ and above) are called baritones.
So does it really matter? I would say – maybe… Most kinds of music have been played on most scales. I’m amounting it all to personal preference.