If you're unhappy using Blender then its very easy to get 3ds Max for free by signing up for the Autodesk education system. I personally don't know blender at all, I've never used it... I used GIMP for a long time and bascially its very good, but I do use Photoshop too now because unfortunately there are certain things that just cannot be done in GIMP (or not so easily at least) I could imagine the same would be true for Blender vs. Max
That aside, there are TWO very major advantages to signing up to Autodesk and using Max:
1) For all Source models and mapping you can dl and install for free the WallWorm ModelTools script. This is a great little plugin (script) that takes a huge part of the headache out of model export and compiling, letting you concentrate more on the modeling itself. It works in conjunction with the SDK, SMD exporter and MDL compiler to automatically create your .qc file (from the properties you select in WWMT) and compiles the models/textures directly into your game folders from Max. Just recently they've even added a script that allows you to bake multiple objects sharing the same UVW space into one texture - a feature sadly lacking for too long in Max. WallWorm has been hugely expanded recently, so as well as all the model compiling tools you now have a huge array of tools for making whole maps in Max.
2) The second major advantage is that signing up for the Autodesk education programme not only gives you access to 3ds max, but also to Maya, Mudbox, MotionBuilder, Softimage (not that you'd EVER want to!!) and many more (It looks like Valve are switching over to Maya officially now, so it may be a good time to think about getting that as well). Its really very easy to sign up and you will be able to use the complete versions of all of these products for free for 3 years. It only takes a few minutes to fill in all the info they ask for (name, address, etc - not much really) and you'll get the software key given to you immediately. Only one thing - THIS SYSTEM IS NOT FOR COMMERCIAL USE, IF YOU MAKE MONEY YOU SHOULD PAY THEM.
(Autodesk education page)