In reply to jackdimples1:
I help support it many times each summer for my wife Anne's groups, which cover everything from biggish charity groups through to self-guided trips wanting some logistics support. Worth contacting Anne on anne@spa-treks.com for advice if you have specific questions.
The walk itself is stunning, certainly the higher days anyway, and quite a challenge for a lot of people. Most groups finish at the trailhead in Spain at the first vehicular access but the 'official' route continues a long way down a road to Alos. This bit is logistically the hardest because even at Alos the accommodation and public transport options are all but non-existent, so having something arranged in advance can help a lot.
Also as above, late June is early season, so expect some snow banks to cross. Crampons pretty much obligatory at that time of year but depending on your experience and competence you may be OK with walking poles rather than an axe.