Talk about the best and worst of times.

In Scotland's tale of two rugby cities, there may never have been a more dramatic contrast of fortunes than we saw in the performances delivered, and results obtained, by Glasgow and Edinburgh on Friday night.

In Newport, Glasgow blew away a hapless Dragons side – on a pitch that contained more sand than the Gobi Desert – with a masterclass of clinical rugby. They were crisp, precise and deadly, claiming eight tries on their way to a record 60-3 victory.

Meanwhile, at Murrayfield, Edinburgh did what Edinburgh have been doing all season, churning through the motions without a single spark of obvious inspiration. By all accounts they were a better team than visitors Cardiff Blues, but there is a horribly flat feeling around the capital club at the moment and it was no great surprise that they finished on the wrong end of a 17-16 scoreline.

But it should be. Edinburgh had home advantage, a host of international players, unimpressive opponents and a point to prove after the effective sacking of head coach Michael Bradley a few days earlier. Strictly speaking, Bradley's contract is simply not being renewed at the season's end, but his departure still comes down to the fact he has committed the cardinal coaching sin of making a good team worse.

How good they were is open to debate. But even if you take the view that Edinburgh's run to last year's Heineken Cup semi-final was the result of a series of outrageous flukes and a few dollops of good fortune, it still revealed the calibre of a number of individuals. Netani Talei, Dave Denton, Lee Jones and Tom Brown emerged as players of real worth. This season, all have been pedalling backwards.

With the possible exception of Matt Scott, it is hard to think of a single player who was an Edinburgh regular last season whose reputation has grown since. Of the newcomers who arrived over the summer, only Greig Tonks has been an unqualified success. Willem Nel has impressed occasionally, but the rest are on a spectrum that stretches from ordinary to disappointing.

Edinburgh's decline is mystifying, but it has been clear for months that radical changes have been needed behind the scenes. How significant, for instance, have been the departures of Mike Blair and Chris Paterson? Both may have been in the evenings of their careers last season, but you do not shed the experience of a combined total of 194 caps without feeling some effect. As difficult as it is to identify Edinburgh players who have improved this season, it is harder still to pinpoint figures who are rallying points in moments of adversity.

Bradley's forthcoming departure has caused no obvious grief among supporters of the club. Through his failure to engage with fans, and with his obvious distaste for the media duties that go with the job, he did himself no favours on that front. That said, he has not been in Neil Back's league.

The most conspicuous of players, Back has transformed himself into the Invisible Man since he took on the role of Edinburgh forwards coach, both in terms of public sightings and his apparent impact upon the players' performances.

Again, the contrast with what has been happening at the other end of the M8 is striking. There is an air of excitement around Glasgow which is not entirely the consequence of results. At Scotstoun they have found somewhere that feels like home, something fans want to be part of, and where the febrile match atmosphere can be savoured as much as the Murrayfield morgue is to be dreaded.

Which is why, even in the heart of the Six Nations season and with a team shorn of Scotland players, Glasgow pulses are already racing ahead of Friday's home clash with Ulster. The RaboDirect PRO12 league leaders have developed a distinct wobble in recent weeks, surrendering their unbeaten record against Munster and then going down to Ospreys at their previously impregnable Ravenhill fortress. Glasgow, sitting second in the table, cannot overtake Ulster on Friday, but a win would have them breathing down the Irish side's necks. Gregor Townsend's side have been favoured by the fixture list in recent weeks – their last five games have been against teams in the bottom five of the league – but their performance against the Dragons glistened with excellence and they should go into the match with confidence sky high.

Good on them, too. But the gap between the two Scottish clubs has grown to an extent that the SRU who own both, are not going to close it by tinkering with the Edinburgh coaching team. Come summer, we can probably expect some eastward movement of players as well, with the first to go likely to be a scrum-half.

Bradley may have said he is happy with the players he has; there are many in Edinburgh who are happier still that he won't have them for much longer.