HELIX template should I expect any problems ?
As long Joomla user (since 2005) - I will say this way, there are problems with every template, regardless of the developer, sometimes it results from errors in the php code, CSS styles, conflicts between extensions, or lack of knowledge of the webmaster. But every problem can be solved. This is not a Mars expedition where help from the ground is limited to radio only.
Many users use the Helix Ultimate website for their businesses (small / middle) or government sites. This shows confidence in the product. With every update HU is better.