150ms are client-side read. But without any js-triggered modifications to the DOM tree, this is pretty much the render time (rendering is 2ms on my not-too-beefy laptop).
Yes, that's quite good. It's pretty common to find server-side actions that take longer than 150ms to just return the page, and 2ms render times absolutely smoke most JS-framework pages.
I stand by my original comment (it's better to avoid loads than to assume you're fast), but good on you for getting those latencies down.
But also, let's be real for a moment: define "latency". Is 150ms your (client-measured) connection time? Your render time? Your usable-page time? Again, most webapps are lucky to get HTML back to the user in under 300ms, and if your 150ms metric is "time to server-side render", then you very likely aren't.