Here's a simple sound comparison video from Pete Alexandar using the affordable AspenMics HQ-S Stereo Lav mics. Using the same two microphones he's recording one to a Samsung Note 4 and to a Zoom H4n. For comparison he references back to what audio would sound like from the internal Sony A7s camera microphone. You'll notice immediately how different the same microphone can sound when using different recorders.
The Zoom H4n obviously is designed to capture quality sound and there's a big difference compared to the Samsung Note 4 which may sound a little flat. Still not a bad thing if you know how to tweak the audio in post using the Audio EQ. If you're looking to pair it with an affordable audio recorder that offers high quality sound capture, my vote is still the pocketable Zoom H1 often found for under $100 bucks.
So if you're looking to get better audio, there's no reason why you shouldn't have a good set of lav microphones in your kit. The focused sound will block out most ambient noise and deliver a higher quality recording. The AspenMics are perfect for the budget filmmaker, finally back in stock, and currently on sale (HERE).
For an additional sound test of these mics, check out the review samples from Ray Ortega from ThePodCasters Studio.