In late June 07 / early July, I travelled solo out from Newcastle to Ijmuiden, Holland; to Bad Lautenburg in the Harz Mtns, West Germany visiting Mittelburg Dora where the germans built the V1 & V2 rockets, Leipzig & Colditz; Kutna Hora (Church of Bones), Czech; Ozweicim, Poland (Auschwitz) & Zakopane; into Slovakia riding in the Tatra Mountain and around the Spissky Hrad area; into Hungary Komarno & Lake Balaton; into Austria (Mariazell); into Italy (Dolomite mountains around Cortina & Timmelsjoch pass); and then to Garmisch for 3 days at the BMW Biker meeting, before the return homeward leg via Cochem, Mosel and the ferry from Ijmuiden. 3,800 miles in just over 2 weeks.
Couple of points about the BMW trip. There are not too many roads in the Tatra's and the mountain area itself is closed to motor vehicles. You can drive round the mountains but not get up close & personal as you do when riding in the Dolomites or Alpine passes. I did not find any big climbs, hairpins or twisties that you get in the other mountains. Polish A & B class roads are not too well surfaced - watch out for suicidal driving. Roads in Slovakia were somewhat better.
Accommodation was plentiful & cheap in all these countries. Nothing was pre-booked except the 3 nights at Garmisch (35 euros per night). Poland cost a total of £50 for 3 nights B&B in a nice guesthouse in Zakopane (out-of ski season the guesthouses were tripping over each other for business). In Germany & Austria it is easy to find good accommodation at 30-45 euros per night - all for single, en-suite rooms. Colditz Castle youth hostel was about 25 euros. Food was cheap & good in Poland. Czech, Poland, Slovenia, Slovakia, & Hungary all still use local currency & not the Euro however cash can be drawn from ATM's as you go or £'s / Euros converted.
I presume BMW will use hotels to cater for the larger numbers they take on tour however if you went independantly with a couple of friends I would think you could each do a similar tour for about half the BMW price, leaving plenty of money for beer & petrol. I only speak a few words of German and have found I get by as English is fairly widely spoken in any area which caters to tourists.
Whilst you may prefer that everything is organised by BMW and you have people with you, it may be worth working out what the trip would cost independantly if you bought your ferry ticket and paid your accommodation as you went.
