I'll discuss Sobotka's not re-signing with The Blues, here, together with the re-signing of Ott, because the latter event only happened because of the former.
I'm unhappy that Sobotka didn't re-sign, and chose to go to The KHL mostly because I wanted the image of The Blues around The NHL to be a team where the players are treated well, players and management have a reputation of having a solid, good relationship, and The Blues known as a team for whom players want to play. That reputation shouldn't be diminished much, as it is clear that the money offered by Armstrong was adequate and reasonable, and that the issue was strictly personal with Sobotka.
Sobotka was very glad to come to The Blues from Boston, because he had had no chance to show what he could do with that team, as there was no room for him to have a regular spot. On The Blues, he played well, and showed what he could do. THEn, this off-season, The Blues overloaded with forwards, upgrading so greatly, that he has likely has been pushed back down to a part-time role, AND part-time only-and bouncing between lower lines than last season (e.g. between 4 and 3, rather than 3 and 2. This is a step back in his career, EVEN if he could, for the first time, be a member of a true Stan;ey Cup competing team, and, if all goes right, a Stanley Cup winner.
Despite the apparent setback to his career efforts, he could have made the decision to bite that bullet, and sign with The Blues for $2.7 million (and take home $1.8 million, rather than signing for $ 3.5 million in Russia, and taking home about $2.7 million), and have a chance to be on a Stanley Cup Winner, show he's very loyal, and show The Blues he can deal with adversity, giving him a chance to "shine" in the lesser role, and making a big impression on Blues' management, for his potential UFA re-signing, or moving on to other teams to sell his loyalty and plug on under difficult circumstances attitude, as a selling point to other organisations,
I am disappointed that Sobotka didn't take the 2nd path. But, I fully understand that he felt that going to The KHL rather than accept the lesser chance to show what he can do on a high level was a better move for his career, at this point. Getting the extra $ million (after taxes) was just a bonus, but not the real reason he bolted. He had thought he had made a place on The Blues, and Blues' management "showed disloyalty to him, by bringing in several better players, and pushing him back down to fighting for a lesser place on The Blues". He didn't like that, and probably felt subconsciously, that The Blues were now being "disloyal" to him, by "tossing him out of the position he had won for himself".
As to the re-signing of Ott. I liked his stepping up of his play in the playoffs. I welcome having him as an extra asset in case of injury, and to use in the playoffs. But, at the same time, I don't like the fact that he will likely take games away from the young, developing players, and the chance to get them better integrated into the team. I'm sort of neutral on his re-signing, knowing that Sobotka was going to be gone either way.
If it were a choice The Blues could make as to having Sobotka back or having Ott in his place, I'd take Sonbotka. If it is a choice to fill Sobotka's roster spot with Ott at $2.6 million for 2 years, or another player, it would depend upon who the other player is.
If it were a choice to re-sign Ott at $1.7 million for 1 year or another player, it would be easier for me to choose Ott than at the current terms.