Duh see what happens when I cut and paste parts of a sentence around... This year I used Black Gold potting mix but I further amend it first. In a large pyrex bowl I add some extra pumice and sand, wet it well and microwave for about 12 minutes. Microwaving helps distribute the moisture throughout as well as sanitizes the potting mix.
The main mistake (experiment) I made this time was to top it all off in each baggie with about one half inch of seed starting mix which is just finely milled sphagnum peat moss. This stuff turned crusty when dry and was difficult to re-wet. I'll skip that next time around.
I too was hesitant about adding osmocote mainly because there is also a small amount of fertilizer in the potting mix. But that is why I mixed it into just the lower portion of the baggie.
I have the same experience when doing baggie vs pot. The baggie seedlings shoot ahead fast, maybe because they like crowding in the beginning. For me they are certainly easier to handle in baggies and I can get many more under lights due to their smaller size and flexibility. But another reason why mine may look stronger than yours is that many of my crosses are tetraploids.
