We have been using AbcPDf for quite some time for the sole purpose of converting HTML to PDF, but we were not very happy with the product. For starters, the DLL was exhorbitantly costly, $4000+ for re-distributable license. Secondly for some weird reason they had different DLLs for 32-bit and 64-bit platforms and were priced differently too. Lastly the DLL itself had a lot of issues with configuration and multi-page HTML conversions, and it seemed it had memory leak issues.
All this took a toll on our product where we were embedding Abcpdf, so we decided to look for alternatives. We tried Aspose.PDF but the experience was horrible. The HTML-PDF conversion was pathetic and the converted PDF was no where near to the original HTML, specially when external style sheets were used. We created a ticket for this issue but their support team has not yet fixed the issue. We really like Aspose.NET product suite, but I still do not know why Aspose.PDF is woefully short on features.
Doing some more research, we found HiQPdf. We were quite impressed with it. The converted PDF from HTML was perfect, and we liked the performance too. And their DLL worked on both 32-bit and 64-bit platforms. The enterprise license was also much cheaper than AbcPDf, for only $1200 USD. I really recommend HiQPdf for HTML to PDF conversion in .NET.