NOR vs. NAND for installation?

This is a super-rookie question but I couldn't find an existing answer.

I'm about to flash OpenWrt on a BananaPi BPI-R3. I have the choice of installing to 32 MB NOR, 128 MB NAND, or 8 GB eMMC.

The BPI-R3 device page explains how to install to each location, but says nothing about why to prefer one over the other.

My understanding is that NOR is "better" than NAND in general, and 32 MB of NOR on this device is far more than I will ever need for the packages I might install.

So, my question: is there any reason not to install to NOR?

The biggest reason I can see for selection of one over the other comes down to the shared I/O configuration on that board. In essence, you have to choose which two of the storage media you want to use, and the other two will not be available.

Some people will want the larger NAND memory for storage of add-on packages, logs, or other data whereas others are perfectly fine with the smaller NOR memory. Some people might even choose to use one as the primary and the other as a manually activated emergency backup option in case the primary gets corrupted. No doubt, there are other reasons I haven't even considered, too. In essence, it all comes down to personal choice, intent, and which options best suit the person's needs.

on MT7621 devices there is a speed advantage to NAND over NOR
due to wider interface on NAND vs SPI NOR
so boot times are very different

Thank you for that information. I'm leaning toward installing on both, then booting from NAND normally and having NOR ready as a backup.