I'm not sure that I've heard about these "ref-rubs" of which you speak, but as far as their similarly spelt neighbours, refurbishments, go, then the Northern Spirit refurb of the 156s was truly superb. When it was a bit fresher, mind, some of those units are looking a little more woe begotten now, which is a shame.
In the same way that it is difficult to objectively select a best TOC because of the wide diversity of routes and passenger markets they serve, it is also difficult to select a single best rolling stock refurbishment, due to the diverse number of different criteria that different refurbs are expected to meet.
I think, therefore, that refurbishment types can be broken down into three basic categories; Long distance, regional and commuter/short distance. I haven't been able to select just one single example for each category, so here are my nominations:
1. Intercity
In first place would be Wrexham & Shropshire's mark 3 refurbishment. If the league table of refurbishment standards throughout the categories is based on the standards of comfort and quality offered to the passenger, then the W&S refurb should top the table.
Following very close behind would be GNERs "Mallard" refurbishment of its mark 3 and mark 4 stock, and also following closely behind this would be BRs 1980s refurbishment of it's mark 3s.
2. Regional
A contest between Northern Spirits 156s, the EMT 158s and Arriva Trains Wales 158s.
3. Commuter/short distance
SWT 455s, Southern's 313s and ATWs Pacers and 150s.
At no stage do the 155s come anywhere near the upper ranks. They're the poor relation of the Super Sprinter classes, that pale into insignificance when compared against the far superior class 156, and they're fitted with those god awful, uncomfortable Chapman seats.