At "less than a year" you're not on up 2nd yr pay, you got maybe 200-400 guys below you. In my case, around 300 seniority numbers, and 8 months seniority, and a crashpad in EWR. A friend told me once he gave FedEx 1 year to give him a call or else he was staying put at Delta. I thought that was pretty good advice and adopted the same mindset.
We're both flying Purple jets.
Although, in all seriousness, I think there's so much more at play than just the time you've spent at a legacy (while very important). Where do you live, how old you are, WHICH legacy is it (1 yr at UAL yields about 200 guys below you, 1 yr at DL... 1000?) etc, etc. I've met people that left UAL after 3 years to come to Purple and people that came straight form newhire training at DAL/AA/UA/SW, late 20's to late 40's.
After having been here over a year, looking back I’d probably bail at the 1-2 year point.
Regardless, good luck to you my friend. It's a fantastic job.