Originally Posted by
txaggiemiles
Upgrading to first may marginally help your chances of finding a friendly agent, but probably isn’t alone enough to justify the upgrade, as there’s a chance you’ll just pay for both.
True, but if the extra allowance is enough such that the OP can use regulation-sized bags, then it's a pretty clear win, IMO (assuming there's an F cabin on OP's CRP-IAH flight and the upgrade is its usual range of $119 or less for that length).