The XC▸ services have got worse - I've changed my morning train as a result, got fed up with the over crowded 4 coach trains (when they used to be 5). The FGW▸ trains are much much better.
Virgin trains took about half of the total super voyager fleet i think (give or take about 5 or so)
Really with the XC services around bristol, it depends what time of day you travel espically if your traveling north from bristol.