From what I can see in Taliafears spreadsheet (my updated version of it, using the same boss profiles though so only pre Ulduar bosses are modeled) the trinkets are certainly competetive. They are both better than
[Essence of Gossamer] (since the Essence proc is pretty bad in any case), and also seem to beat
[Eitrigg's Oath]/
[Fervor of the Frostborn] (unless you really want avoidance). They are not better than
[The Black Heart] or any of the endgame 25 man tank trinkets. Depending on your focus for a certain bossfight, they might be better than
[Glyph of Indomitability].
Modeling the heal for the Bubbling trinket gives the equivalent of 6.3 BV, depending on boss swing speed (6.4 is for 2.5 sec, will be lower for faster bosses). Modeling the 2500 heal as a temporary absorb that is up for one boss swingtime and dividing by the cooldown to get an uptime). So, on average, the use effect is in pointless although it could be useful as a extra health pot if things get hairy.