I think the windows are hard to compare under Robins without the context of the fall and rise of the club during that time and the associated increases in budget that comes with promotion. In L2, despite relegation, we were still a big fish in a small pond. That's 3 of the 5 seasons.
I suppose the 2nd season in L1 is perhaps most comparable to this year, as it's the only other time we've played consecutive seasons in the same division under Robins.
At this point we'd signed:
Allen and McFadzean were seen as solid signings and people were happy we'd finally replaced Burge with Marosi. Dabo was exciting but was replacing Sterling who'd had a good season. It wasn't particularly exciting then either, aside from some Football Manager style anticipation at our new foreign signings. We'd also just sold Chaplin which, while many were not unhappy to see him go, left us looking light up front.
Robins pulled it all out the bag by adding Godden on a permanent using the Chaplin sale money and added O'Hare and Walsh on loan in August and September.
I guess my point is that when you survive in a division, the improvements are more incremental than when you jump up a division, and that the best deals always happen later in the window when the Prem trickle down starts to happen.