Wired vs Wireless Lav. Which Gives the Best Sound Quality and is Least Likely to Fail?

Client just asked this question.  And now I am thinking.  Where do I even begin...

I will start with a wired option.  No doubt it will give you the best bang for your budget buck.  I have and highly recommend Sony PCM-M10 recorder and use it with JK® MIC-J 044 lavalier.  For under $250 you can have an audio recording which may pass for a professional.

Pros:

• Budget friendly: Relatively affordable, much cheaper than wireless solution.
• Simplicity: you need to set one recording level and press one record button.  That's it!
• Ease of maintenance: ensure that just one set of batteries is fully charged.  Sony recorder is using 2xAA batteries and have a terrific running time.  I stick with Eneloop rechargeables since my photography days.  I have so many spares with me at all times I can switch those in under 10sec.  Practice makes perfect.

Cons:

• No realtime feedback.  Is that recording still on?  Is level ok?  You have no idea what's going on until too late.
• Usability: The recorders are not designed to be used while being carried in a pocket.  User can accidentally shift the recording level or even stop the recording completely.  And you will never know until too late.  To somewhat mitigate this, I used cell phone pouch/belt clip.
• Need to synchronize audio. Not a big deal in my opinion.  I learned to do it manually by just looking at waveform.  Also I hear Pluraleyes is really good.  Many NLEs have this capability built-in.  Not Sony Vegas though.

For wireless lavalier setup I use Sennheiser G3.  Check out this Wireless Mic Shootout and this Teardown.  That sealed it for me.

Pros:

• Built like a tank.  Works always.  
• No interference with RF/cellular.  Outstanding range.
• Good quality audio

Cons:

• Professional equipment comes with a high price tag.  
• Usability: You need to set the level of amplification in transceiver, then receiver, then recording equipment.  Workaround: do it once, do not change the components, retain settings.
• Usability: switching a channel is not intuitive.
• Usability: You need to keep an eye on two sets of 2xAA batteries.

Summary: Lack of the real time status for wired into the recorder solution kills it for me.  When on a budget it might be ok.  For payed jobs though a radio lav is a must-have.  It is expensive though.  Plus you need to know your equipment and its settings. And be able to change those if need be.