After all the discordant notes of seasons past, the harmony that has engulfed the Guinness PRO12 just lately has been almost deafening.

The Welsh authorities have kissed and made up with their clubs. Treviso's toys are all safely back in the pram. Johnny Sexton is set to do his prodigal son act and return from France to the green fields of Ireland. Sweetness and light is everywhere.

Well, so we can tell ourselves for the next few days at least. For next weekend all this canoodling will come to a sudden and crunching end as the teams of Scotland, Ireland, Italy and Wales put the summer of rugby love behind them and get back to the altogether more interesting business of knocking lumps out of each other instead.

Time was, of course, when the start of the Celtic competition was a matter of monumental indifference, even to those who were meant to be running it. The mind goes back to the late 1990s and the unmistakable whiff of desperation that surrounded the so-called Welsh/Scottish league, a tournament that mostly seemed to involve Scottish teams making 10-hour bus journeys for the privilege of being beaten (and often beaten up) by sides such as Ebbw Vale and Caerphilly. To call it low key would overstate the hype.

Had you fallen into a coma back then - and by jove it was tempting at times - and woken up at the launch of the Guinness PRO12 in London last week, you would have struggled to believe that you were still on the same planet, far less involved in the same tournament. The runt of the European rugby litter has grown into a strappingly successful competition, has acquired two more countries and is now comfortably the equal, by any measure, of its cousins in England and France.

A blue-chip title sponsor and the interest of Sky Television are evidence enough of that. But so, too, is the PRO12's combined total of 227 international players, representing 14 different countries. Yes, it is still too often seen, and used, as a plaything of the international authorities, but even that factor is diminishing in importance as sides assert their autonomy. And the self-confidence of the clubs is only likely to grow as new European qualification rules reduce the number of meaningless games.

Not that Glasgow have had too many of those in recent seasons. Over the past three campaigns, they have finished the regular season in fourth, third and then second place. The trajectory has been both constant and upwards, the only unticked box being a victory in the PRO12 final itself. In the opinion of many, if not most, coaches at the launch in London, they go into the season as favourites to take the title.

The logic is clear enough, but the Warriors' flat performance in last May's PRO12 final in Dublin, when they were beaten 34-12 by Leinster, inevitably provoked a concern that they had peaked. Certainly, they looked like a side who had nothing left in the tank after the nine-game winning streak that took them to that stage of the competition.

The over-arching question now is whether they have replenished their stocks of enthusiasm and drive. Conveniently, it will be answered on the new season's first weekend. Glasgow versus Leinster at Scotstoun on Saturday may not be a title decider, but it is a tumultuous first match for both sides, one in which points gained will count for less than the psychological boost the winners will take from victory. Away from home, and with some of their Test players ruled out by inter- national protocols, a loss would prob- ably be easier to bear by Leinster; for Glasgow, facing trips to Cardiff and Newport over the following two weekends, losing would be a far more crushing experience.

So can Glasgow improve this time out? Gregor Townsend has performed wonders at the club in terms of keeping things fresh, but this could be his most challenging campaign yet. The coach's summer recruitment has been modest, with the return of Euan Murray the only move to make the headlines and the loss of Chris Cusiter to Sale looking like the only significant weakening of the squad. Overall, Glasgow appear to be in no worse shape personnel-wise than any other side.

Being without Al Kellock for the first few weeks of the season is undoubtedly a blow, but the captain was injured for much of last season and they still came through. The impression from their opening warm-up game, against Harlequins last weekend, was that the Warriors are in pretty good shape in most areas, save that they lost focus near the end and allowed the result to slip away.

And Edinburgh? They are far more of an enigma. Last season may be remembered as one of the most way- ward by any Scottish club in recent times, with the capital outfit suffer-ing a record defeat against Munster, gifting Zebre a precious win, and yet still managing to beat Gloucester in the Kingsholm cauldron. Magnificent one week, desperate the next, the one thing they have to give coach Alan Solomons this season is the platform that a degree of consistency might provide.

If they can do that, it is far from impossible that Edinburgh could clinch the top-six slot that would give them a place in the Champions Cup. That, after all, would be only two places higher than where they finished last season. It is hard to see past Glasgow being Scotland's top dogs for the fourth year on the trot, but Edinburgh have the resources to make the fight a little closer.