Is it worth switching from DCM to CorpBanking for a long term career

My two cents:

DCM --> Corporate Banking is not an uncommon path for someone with seniority to take for better wlb, though it can be rare for juniors to make the jump early on in their career. Senior bankers tend to leave around 6-7pm, and juniors most likely finish their 12-hour days and leave the office by 9pm.

In terms of workflow, although corporate banking is debt-heavy, DCM is only one of the many areas that falls under the collaboration scope of CB. For most brand-name CB's (Citi, JPM, BofA, HSBC, etc), the vast majority of revenue comes from payments (treasury services, TSFX, etc) and markets (investments, liquidity, FX, derivatives). These so-called flows are recurring revenue for the banks so they'd prefer latching onto big names and reap those benefits. In addition, you have your traditional credit products (revolving credit facilities, term loans, letter of credit, etc), but banks have varying focus on this, as big balance sheet doesn't necessarily mean heavy focus on direct, guaranteed lending. I'd suggest you reach out to people working in CB to learn more. 

You should also think about whether you want to be a coverage or product banker in CB, if you already have your mind set on making the switch. It's kinda similar to how things are in IB, you could learn more about different product offerings while covering a certain industry; or you could become a product specialist and only provide that service to clients across different industries. I guess it depends on how your network is structured.