I just went through the same debate and bought a 2x72 about 2 months ago. After several months of research my top 3 were the TW-90, KMG-TX, and Northridge. I ended up with the KMG-TX. It’s direct drive with ratcheting tension,VFD, and has the tilting feature. Price wise they were all in the same ballpark and the KMG offered a 3 hp motor option which is what I got on mine. Honestly at the end it was between the KMG and the TW-90. Mainly because there wasn’t as much info on the Northridge. One deciding factor in my decision was lead time. The TW-90 was going to be about 10 weeks before shipment(I’d still be waiting for it to be delivered ). I had the KMG in 2 weeks. I know that sounds like a stupid reason to base a decision on but I had agonized over which one to buy for so long I didn’t want to wait any longer.
Anyway, the KMG-TX is a monster. Hard to believe anyone makes a machine that is significantly better in a similar price range. I checked a few things with my machinists square earlier this evening and it was dead on. I don’t really agree with the guy in the video’s assessment of the the bolts on the Northridge being better suited for axels. A shoulder bolt would probably be best but I’m not sure if any manufacturers use them for that application.
My main advice would simply be to buy a reputable brand and several have been mentioned in this forum. You can find videos and posts for or against any grinder you choose so don’t get too caught up in that if it is a good brand. I‘d also recommend getting a grinder that uses 1.5” tool arms. That’s ALMOST the universal size. I’d advise against getting any of the “super deal/everything you’ll ever need” packages. They’re tempting but most of the stuff included probably wouldn’t see much use in my shop. I got the articulating rest, small wheel package, contact wheel (included), and flat platen (included) with mine and that’s handled everything I’ve needed so far. The 3 hp motor has been incredible. It eats everything at whatever speed I’m running it and acts like it enjoys it.