My $.02. Are you having issues with planing? With clean kills? If not, why change and risk the failure of a mechanical.

I've bow hunted for 50 years or so now. I have yet to see any issues with high quality so called fixed blades .... either the old styles I started out with back in the 60's or the replaceable blade styles I started using in mid 80's.... making clean quick kills, and being dead on accurate. I have seen significant issues with mechanicals of about every vintage and make including lousy penetration on both broad side and angled shots, failure to open fully, and some mighty weak blood trails. To be fair, I have also seen some hellacious wounds and massive blood trails as well. But not often. The inconsistency I don't like ..... so for my $$$ I stay with what has worked well for me ... and rather recently that has been Thunderheads and Montec. I now use Montec out of a crossbow. Have for 5 seasons with excellent results. Extremely tight groups and clean slicing, with deep penetration or complete pass through. Knock on wood, I have yet to fail to recover ... even on a poorly placed, well back shot that I made last fall.