Probably the biggest difference is independence. Once you have liabilities with the airline which paid for your training and provided Line Training, you are absolutely in their service. Basically you will fly at any time to any destinations. Which is absolutely fine, unless you are not a fan of such “control”. On the other hand if you choose paid Line Training you gain the “luxury” of choosing the airline which you would love to work for and ability to focus on the job which will bring you everyday pleasure.
Baltic Aviation Academy have released an article about why you should do line training:
Line Training: to pay or not to pay?
What is happening to this industry?