I don't have an A40 for comparison; but, as I stated above, the scrolling/swiping speed on my large collection is as fast as you can flip your finger.
On the SD card: I have a relatively older 200 GB micro SD XC I card. Again, browsing is fast.
One more thing: battery life. I am not keeping a spreadsheet of hours of playback. But, I've been listening to my player at the office all week. Taking it home with me today (Friday) and the battery life looks like 50% with an estimated 20 hours of playback (I don't see a way to display exact values).
So, again, mission accomplished: I can keep this at work and not worry about charging during the week. As I use more of the Bluetooth receiver function, battery life may decrease... we shall see.