Originally Posted by
Eisaderfrau
You get a passive buff from Alchemy called Mixology. It makes flasks and elixirs better then their tooltip shows for you if you have the skill to make the item yourself (example: to get the flask benefit from Flask of the Draconic Mind, you have to be able to make that flask).
For flasks, that benefit is an extra 80 of the stat in question. This brings it in line with other professions. The entire reason there is an alchemist-only 80 int repeated use flask is so you can have your profession benefit up at all times for no charge if you choose, such as when questing or doing arenas or any other time when you would normally not use a full-strength flask or would be unable to do so.
If you wish to check, simply check your unbuffed int numbers then take a draconic mind flask. Subtract your pre-flask int from your final number and you will see it is more then the 300 the flask says it provides.
On the topic, what people are saying here is IF you use a potion of concentration on every fight, keep the alchemy trinket. On fights where you do not, tsunami pulls ahead. Since there are some fights where poping a concentration potion is more viable then other fights, your idea trinket choice very well may be fight dependent, at least from the regen point of view. The haste vs spirit is another point, so depending on your need for regen vs throughput, your choice could change accordingly.