Heck, you're probably good enough just feeling the tire, but if you care about the PSI, get the gauge. I have the road morph with gauge and it works well for me.
You don't need to be all that accurate to get back on the road. I just like to know when I get to 60 PSI or thereabouts. I'll kick it back up to 100 when I get home.
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Work: the 8 hours that separates bike rides.