The big differences are that your characters' UPP stats have a much bigger influence on T5 than MGT2. Where MGT2 is mostly roll 8+ with modifiers, T5 is mostly roll under a specific UPP stat with mods and variable dice.
This might not make a difference to your characters, but it is something to be aware of.
Also, some skills in T5 have knowledges, so you might need to do some conversion work, plus T5 characters tend to have more skills on the whole. I think robject who posted above, has posted a pretty good conversion guide somewhere.
T5 personal ranged combat, especially at ranges under 50 mtrs - which for me is most of them - is much more deadly than MGT2. Most of my combats at that range have needed the characters or NPCs to roll under 14-15 on 2d6..... Other than a 12 which is an auto-miss, hits are going to be auto-landed and for a standard shot that will be two hits!
The melee rules in T5 are alas quite broken - or at least in my printed version. In my book two equally matched opponents will be unable to damage each other (assuming they both inject the same amount of dex each round) - so you might need some kind of house ruling. Especially given that many character's stats are on a bell curve with 7 being at the top.