I find the MXR bypass to be quite good in all of their current pedals including the 105Q. I have owned the bass Auto Q and a current Phase90 for years and never noticed any tone leak or loss of tone. They are really quite good for not being true bypass.
Funny thing is that the bypass in the Tech 21 pedals has always bothered me as I can clearly hear that I have less punch in my signal whenever I had one in line. Its a subtle difference and I'm sure I could live with it but it still bugs me.
The Boss pedals are known for having a relatively good but not excellent bypass. I bought a Boss RV5 Reverb pedal last year and was really disppointed in the bypass as my tone was clearly effected when the pedal was turned off but in the loop. It bugged me so bad that I returned the pedal even though it sounded quite good. I find with Boss pedals that having 1 or 2 in my chain is acceptable but adding any more results in a significant loss of tone.
When I was running 17 pedals on my big Pedaltrain board, several of the pedals were not true bypass. All I did was add an MXR Micro Amp at the end of the chain and left it on all the time set to unity gain. It added no noise at all or change in tone, but it restored all the lost punch and clarity from running so many pedals. It worked like a charm.
I have 8 true bypass pedals on my board now but I leave the compressor on all the time and this allows my signal to stay driven and not lose any tone from having long cable runs.
Hope this helps.