Temperature Breaks

When you guys are reviewing your Sea Surface Temperature Charts what temperature breaks are you looking for?

Is it a 4 degree difference? 8 degree?

Also, for those of you that use Terrafin, have you been able to get a clear shot of the offshore waters this week? I use www.SSTCHARTS.com which is free and I have not seen a good shot this week. The best I got was today, but its yesterdays temps.(see below) Is is worth it to sign up for Terrafin? Will I get better shots?

Thanks in advance.