Sir Charles Oman, in the Maida chapter of his Studies in the Napoleonic Wars (37-69) is critical of 'the naval hero' Sidney Smith in the aftermath of Stuart's victory at Maida in July 1806. Smith ignored the siege of Gaeta and went after the 'insignificant Castle of Scilla' in the Straits of Messina. He failed there 'with loss' by a garrison of 250 Frenchmen and attacked a fortress from the sea that was impregnable from that side. Stuart himself wandered off and while gobbling up small French garrisons what he eventually did was reembark for Sicily. Meanwhile, Massena took Gaeta two weeks after Maida, unmolested by either Stuart or Smith and his naval squadron.
Oman also commented on Maida that 'It was...one of the pin-pricks which (down to the outbreak of the Peninsular War) were all that we ever tried against Napoleon's vast continental power.' (40).
Massena's win freed up his troops to complete the occupation and begin the pacification of Calabria which the British abandoned to its eventual fate. It should be noted that 'the better part' of the English army on Sicily was sent to Egypt under General Frazer where it met disaster and defeat.
In Napoleon's Italian Campaigns by Rick Schneid (55) the author noted that both the French conquest of Naples and the British operations in Calabria are only a footnote during the wars. Further he notes that French control of Italy remained unchallenged and the Adriatic would become 'a French lake' along with French naval units operating in the Adriatic. Finally Schneid poses a question on Maida, 'A great victory, or was it?' Interesting to say the least.
Smith's character is one of an ever-boastful adventurer who did not like being subordinate to basically anyone else and always wished to act independently. Collingwood was exceedingly cool when Smith was assigned to him in the Mediterranean and Smith continuously 'inflicted his boastful reminiscences on every guest, from general to subaltern, who came on board his flagship.' (Piers Macksey, War in the Mediterranean, 121). Admiral Lord Barham wrote to Admiral Viscount Keith regarding Smith: 'There seems to me such a want of judgment in our friend Sir Sidney, that it is much safer to employ him under command than in command.' Collingwood only employed Smith because he considered himself the 'lesser evil' than Admiral Knight at Gibraltar, whom Smith was initially slated to relieve and replace. Collingwood did not want Knight with the fleet. (Macksey, 122).
So, it appears that Smith was an unreliable subordinate, not completely trusted by his superiors and continually reliving his experience at Acre. Interestingly, when he had the chance he would not attempt to land himself and some of his Marines at Gaeta to support the defense, though the commander there probably didn't want his services.
The bottom line it seems is that Smith was a supreme egotist who was more interested in enhancing his own reputation than being a loyal subordinate.