First of all - as far as I remember we got the answer but not through forum (and I bet it was similar to the one above).
Since that time we've done several load tests using Tersus technology. Last time we did it was 3 months ago. Below you'll find short summery of these load tests.
1. Hardware (1 server): 4 x 2 Core i7 920 2,67 GHz; 8GB RAM HDD RAID mirror;
2. Software: Tersus 1.3.44 with Postresql 8.4.1; Tomcat 6.20 set to use 5GB Heap memory
3. Application: Modified version of NeoHair.com. Small modificatiions were done to be able to perform and measure tests.
4. Tests overview: Client computer with web browser entered application and started test using start button (this button was one of modifications we've done to NeoHair to be able to perform tests). Then application automatically simulated user behavior (clicking different, ordered application menus and buttons). The test scenario was mostly searching, but every circle of scenario generated insert or/and update to the database.
5. Load: As end users we used 25 computers with 3 web browsers (Firefox or Chrome) running tests concurrently on each computer. So we had 25*3=75 running web browsers.
6. Results: Server 1 min load avg was: 0,2. Processors had avg 5-20% usage.
7. Results comments: Normal users do not click all the time. They usually have breaks and work much slower then web browsers in our tests (web browsers acted without breaks). That is why we simulated load from much more then 75 users. Our collected data shows that we simulated at least750 concurrent users. Server was able to serve much more users then we simulated. Avg server response time was not affected at all.
During the other load test session on very small server (Celeron 1,2 GHz) we noticed that much bigger load then server can effective serve results in a slow response time for client computers but sessions are performed correctly and whole environment is stable.
Hope it will give you some input about Tersus performance. In my opinion the platform is not only stable but resource effective and able to support heavy load installations. As you can see there is a lot of possibility to enhance served load (like separate machines for DB and Tomcat)
hope it helps,