We actually bought Lispworks (half the price of Allegro), and are using portable allegroserve. My partner (who is a software architect by trade) learned lisp for our current start-up and is using slime on Emacs for his interface so we can switch to Allegro if we want later on, which we are considering for their native high-speed mysql interface assuming it performs as advertised - we're using ClSQL right now to talk to MySQL.)

He is extremely happy about lisp, especially after hacking java for years. (The code-base I had built up over the last few years as well as PG's writings helped convince him to give it a try even though he was very skeptical about lisp at first, There is no going back now :)

Ironically, we decided on a different (more focused) idea to pursue for the current startup for which my architectural firm is the current first customer (my hair was on fire for this app), so the initial code base is waiting for a later date. (It will be used to extend the feature set of the current app by adding a conceptual interface)

My partner is concerned about Aserve's ability to handle massive numbers of sessions at the same time, so we are considering going to a java websever and using the lisp side to generate all the html. (The html macro in Aserve is proving very fast and reliable) We're definitely looking for the best solution out there right now as we are planning to go live in about 2 months.