Head-to-heads
Exactly two machines per page, spec by spec, with the winner marked on each row. The Singer Heavy Duty family is the one three-way exception because that is how people search it.
Juki TL-2010Q vs TL-2000Qi
Same 1,500 spm straight stitch. Owners say the 2010Q adds a speed control and sub-tension dial; Juki's page gives the 2000Qi a trimmer on heel rock and a push button.
Brother 1034D vs 1034DX
The same 3/4-thread serger with the same three feet. Brother's own pages give the DX an LED and less weight, the D an accessory tray, and list the DX $30 cheaper.
Singer 4423 vs 4432 vs 4452
The Singer Heavy Duty family compared as people search it: Singer's own pages list 23, 32 and 32 stitches and three bundles.
Brother 1034D vs Juki MO-654DE
The value serger against our pick. Same thread counts on paper; the Juki is the steadier build for people who serge every week.
Singer 4411 vs 4452
Same 1,100 spm, 84 W head on Singer's pages. The 4452 adds 21 stitches, a one-step buttonhole and a walking foot; the 4411 is the stripped base model.
Singer 4411 vs 4423
Singer lists the same 1,100 spm, 84 W motor and frame on both. The 4423 adds 12 stitches, a one-step buttonhole and a needle threader; the 4411 is the stripped version.
Janome HD3000 vs HD5000
Janome's spec tables match line for line: 18 stitches, 6.5 mm width, 18.7 lb. The real decision is bundle, needle threader and dealer price.
Janome HD1000 vs HD3000
Janome lists the HD3000 with 18 stitches, a rotary hook and foot pressure adjustment; the HD1000 has 14 stitches and none listed.