Hi,
#Product vs Services
learning is in both.In product companies in india bug fixing is more but in project you get the chance to do new code and learn new technology.from this perspective t-sys seems good..
and for work in product companies in
java field is mainly on swing thats I dont think much innovative work.. if you are in c,c++ then working on product is really challanging and innovative.
#Onsite
t-sys may be have only initial/short term onsite to germany.I-flex may have better options in service.. but in product division I think no onsite
#pay wise
t-sys will pay more..
#doamin
for finance iflex +
for telecom t-sys +