In all fairness, the Ar234 was a bomber, so lives outside the "best fighter" box...it dwells in the shadow of the "zoomies" so never really gets the accolades it deserves.
As far as the Me262's operational losses are concerned, here is a quick listing of several incidents I have on hand:
19May44 - WkNmr 130002, training incident; Ufz. Flachs, killed
16June44 - WkNmr 130008, training incident; Fw. Becker, injured
30July44 - WkNmr 170058, engine fire; Fhr. Kaiser, bailed out
23August44 - WkNmr unk, crash on T/O - I./Kg51 (first incident)
23August44 - WkNmr unk, crash on T/O - I./Kg51 (second incident)
17September44 - WkNmr 170298, landing incident; Fw. Bertelsbeck, killed
28October44 - WkNmr 110479, nose gear collapsed; Oblt. Schall
2November44 - WkNmr 110368, crash on T/O; Uffz. Zollner, injured
6November44 - WkNmr 170045, engine failure; Ofw. Baudach
20November44 - WkNmr 170107, crash on T/O; Ofhr. Schope, killed
26November44 - WkNmr 110373, test flight crash; Ofw. Alt, killed
2December44 - WkNmr 110551, training crash; Ogfr. Mentzel, killed
9December44 - WkNmr unk, wing seperation; Hpt. Kornagel bailed out
10January45 - WkNmr 17098, landing incident; Ofw. Weise, killed
I could keep going, the list of these incidents is a long one, but this gives an idea of the hazards of flying the Me262.
And none of the listed above are related to battle damage or combat...