I just purchased a bag of Plagron Batmix. It's a soilmix with peat, perlite, guano and wormcastings (quite expensive at 12 euro for 50 liters / 15 bucks per 13 gallons). I thought I'd give it a try and see if it works better than regular potting mix that I'm using (I tend to add some sowingm ix and perlite to lighten the soil.. and start with nutes earlier).
The ingredients are white peat, black peat, fibrous peat, perlite, worm manure, peruvian bat guano and it has a pH of 6.5 - 7.2 which seems rather high.
Plagron® Batmix is composed of the finest, carefully selected types of peat. By adding various types of fiber and perlite in a lightness and oxygen level that you can expect of Plagron quality earth alone. The abundant presence of Plagron® worm humus guarantees a high biological life, and an even further improvement of the water flow. The most important nutrient to the Batmix is added is bat manure (Peruvian bat guano).
The reason for my choice? I had plants in a regular mix that did "normal", plants in a self made mix that did "better".. plants in a self made mix with added nutes that did "good" and plants that I discarded (but put in compost to see if they would do something) that did GREAT. So I'm really interested in what this stuff will do.