No experience with the non-Topstone options, but I provided my thoughts on the Topstone in this thread:
Lots of Topstone recs, so I thought i’d offer some thoughts on my Topstone.
I was also recently in the market for a budget gravel bike and went with the allow Topstone Apex 1 . It’s been great, thus far, and has been getting more use than my road bike and mountain bikes .
I mostly went with the Topstone because the price was right and I was curious about using a dropper post on a gravel bike. I’ve been pretty pleased thus far, with a few quibbles. One thing to note is the 1x stock gearing feels a little limited for my fitness level (3.2 w/kg) and geographic area (also Nor Cal). I tend to ride lots of singletrack other rides that would be more appropriate for an XC mountain bike and sometimes found myself wanting a bit more than the 42t granny gear out back. An upgrade to a cassette with a 46t granny gear cured this (the Apex derailleur handles this fine, despite claiming a 42t limit). Another quibble is that the bottom bracket feels extremely low. This only presents an issue if you intend to ride singletrack with exposed roots and rocks, and likely won’t impact you on gravel roads. The low BB can lead to pedal strike in places you would not expect, especially when you’re drilling it on singletrack and not being terribly careful with your pedal stroke. The plus side (and I consider this a major plus) is that the low bottom bracket contributes to a very stable feel while descending. I’m too lazy to check the geo charts and compare with other gravel bikes, but I have have found the bike to be a ripper on descents - the dropper post is huge factor contributing to this, and I suspect the head angle and geo reflects this descending/stability emphasis. I don’t care about the weight penalty of the dropper and I don’t think i could go back to riding gravel without one.
If going up hills as fast as possible is the only thing you care about, you might find the bike a little portly and sluggish for the aforementioned reasons that contribute to the descending prowess.
I think the Topstone is a good choice if you intend to ride a mix of singletrack, fire roads, and rutted out fire roads that act more like trails, and don’t value weight savings above all else. If you intend to ride roads that happen to be gravel, and care a lot about weight, consider looking elsewhere.