A little extra room = middle seat blocked in Club. So long as you're aware that this is the only extra space you get and the seat / legroom is not bigger as is the case on US domestic First Class.

2x 32kg checked bags per person in Club as opposed to 1x 23kg checked bag in Traveller.

Club lounge access (complimentary drinks inc alcohol and limited food) at LHR and a similar but not quite so expansive 3rd party lounge facility at CPH for Club as opposed to no access to lounges in Traveller.

Complimentary on board food and drinks in Club, although the food offering is quite meagre at the moment, I believe this is being revisited later in the year (so make of that what you will) compared to buy on board food and beverage in Traveller.

Advanced seat assignment will cost $ in either cabin to non-status passengers. Both open up as being free of charge when online check-in opens T-24hrs before departure.

Group 1 boarding for Club
Group 4 boarding for Traveller (no status)

Taking all of this into consideration, only you can decide what's important and constitutes value to you and the way you travel as to whether the additional mileage spend is worthwhile. It's important to understand what you get/dont get in each class, especially when you're not used to travelling with BA.