Continental +'s:
- elite bonus
- possible upgrade to F when flying CO/NW domestic
- can accumulate miles on CO/KL/NW, including elite bonus and status miles

Continental -'s:
- their FF program is not what it was (redemption and upgrades hard to obtain, among other things)
- if flying through EWR, you'll have to clear customs and deal with the TSA for your domestic leg


KLM +'s:
- excellent FF program IMHO
- can use miles to upgrade any fare (unlike CO, BA)
- can accumulate miles on CO/KL/NW

KLM -'s:
- their redemption levels are not very competitive if earning miles as a non-elite
- I understand KLM uk's service is substandard (for your DUB-AMS leg)


BA: I don't know their FF program well, but was under the impression it did not grant miles for discounted economy tickets to its European members.


[edited for accuracy]

[This message has been edited by monahos (edited 01-11-2003).]