The game saw one of the fastest goals recorded in Premier League history as the Blades still - after five games are looking for their first win in the top flight.
On the evidence of this display, with three wins from five games now, Reading appear a side more than capable of avoiding any kind of relegation drama.
As for the sorry Blades, a long season of struggle beckons unless manager Neil Warnock can somehow find a cure to his side's inadequacies - both in defence and up front.
Captain Chris Morgan is struggling because while he is a grafter, he was soundly beaten for pace for Doyle's quick-fire opener, and then left floundering when Seol added the second.
Unfortunately for Warnock, he has yet to field record £3million centre-back signing Claude Davis after his arrival from Preston over the summer due to a knee injury.
It is up front, though, where United's problems are most acute as they again struggled to create chances, with Hulse's reply a rare effort on target.
Warnock is clearly going to need all the help he can get from the new addition to his backroom staff this week in experienced coach Brian Kidd, who looked on from the dug-out, if United are to haul themselves out of the bottom three.
From the off, though, this was one of those days for Warnock as Reading were lightning fast out of the blocks.
Despite United kicking off, they lost possession when a long punt up field from David Unsworth was safely cleared by the visitors.
Bobby Convey took up the play and his lofted through ball found Doyle who initially held off Morgan before burying a 12-yard left -foot shot beyond debut goalkeeper Ian Bennett.
Signed from Leeds in the summer, and standing in for Paddy Kenny due to a groin injury, Bennett then made a crucial save in the seventh minute.
With the Royals pressing around the United penalty area, the ball eventually made its way to Seol who unleashed a fierce right-foot shot that Bennett turned aside.
Bennett, though, was saved by his woodwork when was beaten by a James Harper right-foot drive that crashed off the right-hand post before United scrambled clear the rebound.
With United under pressure, a tight-angled shot from Leroy Lita deflected off Morgan and into the sidenetting soon after, leading to agitation from the Blades fans.
That turned to fury in the 25th minute when Seol broke his duck for the Royals following his £1.5million summer move from Wolves.
Nicky Shorey's forward ball found Lita with his back to goal, and he in turn fed Seol who turned inside Morgan before beating Bennett with a low 20-yard shot into the bottom right-hand corner.
Reading goalkeeper Marcus Hahnemann was barely troubled in the opening 45 minutes, and when the half-time whistle sounded there was an unsurprising chorus of boos from the home faithful.
If Lita had converted one of his two chances in the opening 10 minutes of the second half then it is likely the furious United fans would have reacted even more strongly.
Lita flicked a right-wing cross across the face of goal in the 51st minute, that after the ball had earlier appeared to have clearly crossed the line for a United throw.
Then three minutes later Lita came closer still in rising unmarked to meet a right-wing free-kick from Convey from 10 yards, only for Bennett to produce a superb fingertip save.
After weathering another Reading storm, United then managed to haul themselves back into the game just after the hour, with Hulse ending the club's six-hour goal drought.
Chris Armstrong's left-wing cross was nodded on from Ade Akinbiyi into Hulse who held off Ibrahima Sonko before delivering a firm right-foot shot from an improbable angle inside Hahnemann's near post.
The American finally made his first save of the game in the 86th minute - underlining United's lack of creativity - in pushing wide a 20-yard right-foot shot from substitute Keith Gillespie.
But despite four minutes of added-on time, United failed to conjure an equaliser, with more boos ringing out at the final whistle.