Tax is seasonal. Audit is ongoing!
It really depends on if you like a challange or just want to plug numbers. IMO
Tax is plugging numbers...at least that's how I see it. Yeah, you have to know tax code, but it's all a computer program that spits out the numbers.
I find Audits intriguing and fun. I always wanted to go into Forensics Accounting. Trying to find the frauds in financial statements and those imbezzling. Although, Auditing is much more than looking for deception. A lot of it is verifying that all transactions are recorded accurately.
So, it's what type of work you find enjoyable. I'm sure in your work through school you've experienced both.