The team at TDLC were very helpful with our migration to Office 365 from Exchange 2007/2010 mailboxes as well as migrating users emails off-site (using OWA). They also helped us migrate some custom applications along for free using their Migration Tools toolset! We didn't have any issues during this process so I can not comment specifically about that however they are always quick in responding via email or phone when you need them quickly - it's great having someone who knows what we're doingโฆ