The 4 foot 2 tube florescent fixtures originally had Sylvania cool white deluxe 40 watt F40 E7D3 tubes. Replaced them all with Satco s29907 17 watt 2200 lumen LED tubes. Removing the transformer from the first fixture and rewiring the fixture for direct power LED tubes took me maybe 20 minutes, but after that I was able to rewire a fixture in 5-10 minutes. Pretty simple procedure really. The fixtures and bulbs were original from early 1998, some of the bulbs were starting to flicker and all had black rings on the ends to varying degrees.
I installed a Lux meter app on my phone and took before and after Lux readings. As detailed in the table below the increase in lighting was dramatic; roughly 3-4 times increase in light - reminds me of when the florescent fixtures were brand new. Lots more light while using 57.5 percent less electricity.
Location Before After Workbench 172 666 Work counter/desk (dedicated fixture) 366 952 Table saw extension 212 832 Band-saw 79 400 Drill-press (in corner) 93 347 Planer 155 677 Table saw (original F40 tube was flickering) 117 767