1. The entire speaker is unstable, and will move forward and backwards slightly when playing.
Installing stands to prevent the speakers from doing this, is an must of you want to hear what the speakers are capable of. As soon as I installed my DIY stands, I noticed an immediate improvement in bass and midbass definition, image focus, and slight improvement in dynamics.
2. Use of relatively cheap x-over parts.
I am not sure if this is still an issue, but it was with pre 3.5 models. Swapping out the caps with same value, but better quality caps, improves overall clarity.
I understand that Magnaplanar is doing their best to deliver a great price to sound quality ratio, and they succeed very well. That does not mean that a bit of low $$ DIYing can't squeeze substantially better performance.