question about upgrades and returns

i am elligible for a full upgrade.

say i buy the vibrant with the upgrade and use it for a few days and I hate it.  if i return it, will i be able to "re-use" my full upgrade on the mytouch slide?

my dad was able to exchange his upgrade that he didnt like (used it around a week)

should be fine as long as you do it within the 14 day allowance

i am elligible for a full upgrade.

say i buy the vibrant with the upgrade and use it for a few days and I hate it.  if i return it, will i be able to "re-use" my full upgrade on the mytouch slide?

You have either a 14 or 30 (only valid in CA) day buyer's remorse period when purchasing an upgrade.  If you return it within those timelines, they will revert your contract and your upgrade eligibility will remain what it was as if you never upgraded.  However things get a little sticky depending on where you buy your phone from.  If you buy your phone from a 3rd party, they may not have to honor the remorse period.  So stick with T-Mobile CC or Retail.  Retail makes it a bit easier because you can return the phone in person.  If you don't like it and bought it from CC, you have to pay to mail it back and get a tracking number, call up, CS will send you to the Customer Loyalty and order the phone at whatever discount level you were eligible for.

Be aware that, unless the policy is changed, when you purchase online you have to ship the phone back when you return it.  I don't think you will get your upgrade credit back until their shipping departments records receipt of the phone.  Make sure you save any paperwork and record your tracking number.  When the shipper reports phone as delivered, print off a copy showing that. I don't think you will get the next phone until it is recorded that you returned the first one.  If you are uncertain about keeping the phone I would encourage you to purchase it at a corporate T-Mobile store, not third party.