What an airliner would prefer between two students with the same CV with the only difference of ATPL distance learning for one and ground courses for the other?
Doesn't really matter, in the end you'll be issued a CPL (Commercial Pilot License) like any other pilot who successfully finished flight training, it won't be stated on your license if you did it via distance learning or full time. What matters to the airlines is that you can safely fly an airplane from A to B.
Regarding your second question, distance learning (DL) or full time course. Well, in terms of money DL is less expensive and a very appealing choice to many peolpe, but it is certainly not the "easiest" way. DL requires a high degree of determination, discipline and motivation and you must certainly be an autodidact = lone warrior! It must be clearly said, that this form of studying is not suited for everyone. I did a DL course myself and I must say keeping up the motivation over a prolonged time, turned out to be quite a challenge! Personally I would never do a DL course again!
Certainly, full time ground school is more expensive as DL, but in my opinion it has many advantages over a DL course. For example, personal introduction and explanation of (difficult) subjects and face-to-face support by ground instructors, class community which is a great contribution to motivation, time schedule/deadlines which must be adhered to (no delays due to lack of motivation as during DL). But the main advantage (in my opinion) is, that it's generally the fastest way to get the extensive ATPL theory out of the way! And in the end time is money, the sooner you are done, the sooner your career can take-off! So, is it worth it? sure!
Good luck
