In my limited experience or Belgium VFR, its a piece of cake.
One sunday in February I routed Manston - KOK - Diekirch VOR (Luxembourg) and on to Germany.
If you go that way, make sure you get onto Ostend Appr nice and early as once you cross the FIR you are straight into the Ostend TMA. I told Ostend what I wanted to do, i.e. KOK - DIK at FL55 (VFR) and that was fine.
Once at the edge of their bit they handed me onto Brussels Departures, who put me at FL60. I guess they couldn't handle a VFR level. Then they handed me onto Brussels Control. With about 20 miles to run to the Luxembourg border, they handed me onto Luxembourg Approach, who was a very funny English guy. He assumed that because I was at an IFR level then I must be IFR, so I volunteered to go back to a VFR level, not that it seemed to make much difference as he wasn't exactly busy.
On the way back we routed Frankfurt Hahn, Chievres (CIV) to KOK. As we approached the Belgium border, Langen Info told us to call Brussels info. We told them what we wanted to do and they said that that was approved. When we got near Charleroi, Brussels Info handed us off to them to cross their zone, then back to Brussels before Ostend Appr...
They all speak perfect english, so it was simple, although we didn't go too near the main Brussels airport.
Let us know how you get on.