A few months ago I would have recommended WH4L but after the last few weeks, I have done a complete 180.  I agree with what everyone else has said regarding trying to run multiple portals against their shared hosting plan, and I can speak from experience that it is simply no good.

I'm sure if you're going to pay them $50+/month for a VPS, you'll be okay.  I thought I could get away with their $9.99 /month plan and for a while I did, but the db servers are constantly going down now, and I'm needing to log urgent helpdesk calls on almost a daily basis.

I am switching providers - I should have done it sooner but didn't want to take on the added expense.   I decided to go with 1and1.com's shared hosting plan because I've heard other folks have had good luck with them.  Maybe someday I can go the VPS route but I'm not ready for that.

Stay away from WH4L if you plan on doing anything important with your DNN portals.

Can't speak for the performance at 1and1 personally (yet), but the $15/mo microsoft shared hosting plan seems very competitive.