Being both LH Senator for many years and BA Gold for more than a decade, I really do not understand your assertion that LH Senator is like BA Silver. I suppose each programme has features that are more important to some than others, but as an example, BA almost NEVER honors its guaranteed booking guarantee for Golds, while LH ALWAYS honors theirs for SEN.

Actually, I think both your sister's best friend and you are both partly right. It is best to concentrate flight activity on as few accounts as possible to maximize elite status, but I believe it is prudent to maintain accounts with all the major airlines if one is wanting to maximize their earnings in this FF game. Different promotions from different airlines offer many opportunities. For example, in the past ten years I have accumulated mileage and redeemed travel awards in DL, US, WN, AA, BA, UA, CO, NW, YX, and FL. I could have easily not used several of those, but various promotions, bonuses, and other offers made it best to accumulate miles and points in each program at different times. So basically, for all non-flight activity I take advantage of whatever rental car, hotel, dining (iDine offers can vary significantly between partners!) or other offer is most lucrative and build up my balances in each account knowing that eventually I'll have enough to redeem for something when the time comes. A great example of how this proved useful is my CO account ... I hardly ever use it, but have accumulated miles over the past 10 years here and there from different promotions and other activities that were lucrative at the time. A few years ago there was a great full-Y MSP-LGW fare available that I bought tickets for my wife and I, and conveniently enough I had accumulated some of the miles I needed to upgrade those tickets already. I didn't know what I would need them for when I accumulated them, at the time it made sense to take them in CO, and I knew they would be useful some day, and sure enough they were. I topped up the account from AMEX, and I was set for my upgrades without having to pull all the miles I needed from AMEX.

I am not an expert in all FF programs but if you are based in France and even rarely buy C tickets - I think BA has a very good program. Just 2 roundrips with OpenSky (if you fly to NYC of course) will get you to Silver with lounge access or 1 longhaul roundtrip with BA itself plus one roundtrip to London. And Gold is not much further.

Actually I am grateful to you since I am seriously considering a switch from BA/UA to AA/LH combination. You guess I have no personal experience of being a Senator, just comparing official features and reading this forum. So far BA cleared me on the flight with no availability (must admit needed it just once) and was rather good to me slightly bending the rules when I was in a mess though I have never got an op-up or something like this (which I admittedly did get from LH just as *G from UA). I read a lot of disappointment here among LH Senators. Formally comparing benefits it seems that BA Silver is in between of LH Frequent Flyer and Senator but I would be happy if I am mistaken.

Regarding guaranteed bookings, I would say that I have probably tried to use it with Ba on at least 10 occasions, it has worked maybe once. If I have tried it on Lh 10 times, I have been cleared 10 times. It goes deeper however as when one tries to use it with LH, any agent you deal with immediately knows about it and will even suggest it, while at BA the average agent has no idea what you are talking about and it takes them forever to try to implement.

Overall its true that there has been a lot of disappointment among LH Sen's, then again there has also been a lot of disappointment over the years among BA Golds as well....