I'm looking for advice from some more seasoned travellers on packing for a forthcoming trip. I like the idea of carry on only, but I don't think that will work for coming home as i'm planning on doing a lot of shopping in the USA. I don't want to buy multiple luggage items but i'm not adverse to buying a bag that can be carry on on the way out and be checked in to come home. Once in America i'm going to be moving around a lot, mostly by public transport.

Assuming I check my luggage going both ways, which of the following bags would be best (flying British Airways). I haven't actually measured any of them yet so for now we'll assume they're all ok

Bag 1- A large backpack. Old and somewhat battered. Vaguely military in appearance so hopefully would be treated with respect by TSA. High capacity but long and thin so needs to be packed carefully, I'm concerned that if it did get unpacked by security it might not be repacked very well.

Bag 2- A large sports bag (I think Americans would call it a duffle bag?). High capacity and easy to pack, although securing the zips would be an issue. Generally in decent condition but one end pocket is destroyed. Major disadvantage would appear to be that it is a pain to carry around. Nice and comfy to sit on though

Bag 3- Hard shell suitcase with wheels. Slightly scratched/scuffed. I hear these things burst open if stuff gets dumped on them when they aren't fully packed- any truth in that?

Moving onto the only checking bags going one way option... would a backpack be acceptable as the personal item if I also had a high capacity carry on? The one I have comes inside the BA permitted dimensions quite comfortably but it would have a fair amount of stuff in. Are the dimensions listed on BA's website consistent with the LHR sizers? http://www.britishairways.com/travel...n/public/en_gb

Also, would LHR security be ok with toothpaste and deoderant in carry on luggage? Would a roll on deoderant be better than spray on or vice-versa? I'm going to assume that a full size bottle of downy would not be accepted in carry on luggage by TSA at Philadelphia? (My mum wants me to stock up, you can't get it here)